The Tint

How deep is your love?

The thought: Many of the habitats we wish to replicate are very shallow in depth, relative to their width. Something we should consider in our aquarium design and execution?

I don't know about you, but for about the last maybe 15 years, my preference in aquariums has always led me to the "shallow, wide" footprint. This was very popular in reef keeping, as it put minimum distance between light source and corals. And I've noticed that this footprint is more and more popular with freshwater planted aquarists, too. 

My last custom acrylic aquarium had dimensions of 40"x40"x22" (101.6cm x101.6cm x 55.88cm), 152 US gallons (575.38L)- and it created an amazing seagrass biotope tank. I had it re-finished, refreshed, and modified a bit, and it's going to become my ultimate Igarape tank in the near future! 

I'm thinking even shallower (is that a word?) tanks are a cool idea for botanical-style blackwater aquariums (and for brackish tanks, too!), because they are proportioned correctly to mimic the relative water depth of the unique inundated Igapo forests or African vernal pools and Asian streams that hold a lot of fascination for us! If you do a little research, it turns out that many of these bodies of water a stunningly shallow, and this has interesting implications from both a functional and an aesthetic standpoint. And there are a number of commercially-made "production" tanks in these types of dimensions.

An interesting study of just one Igapo area in the Amazon revealed interesting "stats" in regards to depth of water and leaf litter.

In an area where the water depth was a maximum of 2 meters, the leaf litter depth was only about 20cm. In a very shallow side tributary, the litter depth was 10cm (about 4 inches), with the water level above it only 30cm (about 12 inches)!  Now, these are just a few of many different areas affected by seasonal inundation, and there are areas that are several meters deep during peak months. However, on the average, many of the little Igarape that I found information on were at best a meter or two deep, with correspondingly deep leaf litter beds.

Obviously, most of us aren't going to use an aquarium that is much more than a meter in depth, but we can always utilize the ratio of water to leaf litter/substrate and play with whatever dimensions excite us. Nonetheless, I'm a big fan of shallow/wide, because if you do build up a nice botanical/leaf litter layer, you don't have a huge column of water above, and can really focus on some of the bottom-dwelling fishes which make these areas home.

I think an ideal tank dimension for a leaf-litter biotope-style aquarium would be something like 48"x 18"x 16" /121.92cm x 45.72cm x 40.64cm (about 60 gallons/227.12 L)...shallow and wide, indeed! With these kinds of dimensions, you could create a leaf litter bed over a thin covering of fine, white sand, with a depth of about (4 inches/10cm) and a water column of about 12 inches/30cm above it. This is a very good simulation of this type of habitat.

With a relatively low profile tank, you're not likely to feature Angelfishes in this tank! Rather, you'd focus on fishes like characins, including the leaf-litter dwelling "Darter Characins like Aphyocharax, Elachocarax, Crenuchus, and Poecilocharax. For interest, you could introduce some biotipically appropriate Hoplias and Otocinculus catfishes, too. For the "upper" water columns, you could play with specimens of various Hatchetfishes and Pyrrhulina, killies like Rivulus, and cichlids, such as specimens of  Apistogramma, Aequidens, and Crencichla. 

 Obviously, this is just a guide based on some studies of these areas, and you can create your own species mixes and even specialize in one or two featured species found in these habitats (that would be VERY cool!). The important thing, in my opinion, would be that you are attempting to create a few different aspects of these unique habitats. Filtration could be provided by either a canister filter or an outside power filter, with flow directed towards the surface. Water temperature, based on studies, would be perfect if you could keep it at about 26 degrees C/78 degrees F.  Now, the pH of many of these habitats that were surveyed averaged around 3.5-4.2- extremely acidic water with no real ionic content, that, as we've discussed previously, is something that is challenging to achieve, and equally as interesting to maintain (notice I said "interesting", because it's not impossible...just challenging). Thusly, a modest-sized aquarium operated at low pH would be a great "testbed" for various types of research into the maintenance of these types of biotopes. 

We''ve noted from field studies that the primary decomposers in these low pH leaf-litter-habitats are fungi, and different types of bacteria. Fungi are most fascinating, because we see their "work" in botanical aquariums often. Those "yucky biofilms" many of us observe and bitch about on our leaves and botanicals are also visible fungi colonies...so we have some experience with them.

A shallow aquarium such as the one we're discussing would be perfect for observing and feeding challenging fishes, like the "Darter Characins", because they tend to be more difficult to acclimate to prepared or frozen foods. Feeding small quantities of living foods in a shallow aquarium would create ample opportunities for "target feeding" experiments with them! 

Another advantage of a shallow, wide aquarium is a large surface area relative to the tank capacity, which can facilitate great gas exchange- something pretty important if a third of the tank capacity consists of decomposing leaves and botanicals! 

Now, you don't have to build a custom-dimension aquarium. You can always simply partially fill a taller tank to achieve the ratio of water-to-substrate that we're talking about. I suppose one could argue that a deeper aquarium, filled well below its capacity, could more safely accommodate fishes that tend to jump, like RIvulus and Hatchetfishes!

Shallow and wide...good dimensions to play with, IMHO.

Sooo...this is just another one of those "botanical brainstorming" sessions...a little bit of context provided from nature, along with some thoughts about how/why we could incorporate some of these ideas into our aquariums...Let's see who's up for this! I'd love to see some of the stuff you are working on in this area! So many things to learn and discover...it's all very exciting!

As always, feel free to share pics, ideas, and successes...and failures, too. We learn from all of them!

Stay innovative. Stay focused. Stay excited.

And Stay Wet.

Scott Fellman

Tannin Aquatics 

Know thy neighbor: Lessons from nature on fish community composition.

We spend enormous amounts of time trying to create interesting, colorful, and harmonious fish communities; it's not only fun to do, but it's essential to creating a successful aquarium. Everyone knows that a properly-selected group of fishes will create an environment that achieves all of these objectives and more. We do all sorts of research to figure out the best combinations. 

For some, it can get really overwhelming- sorting through all of that literature and ferreting out suggestions from other hobbyists!

There is actually a better "source" to turn to...Ask yourself this:

Couldn't there be some information we could glean by looking at naturally-occurring fish communities in our target area? I think so! Let's take a brief look at a community of fishes derived from a study which took a random sampling of various Amazonian igarape habitats, and consider how the findings could help create an interesting assemblage of fishes for our aquariums! Now of course, in my typical hobbyist's zeal and sloppy research fashion, I took great notes but forgot to write down the name of the study... urgggh! :(

First off- some interesting facts!

In the sample area, the average depth of the leaf litter was an astonishing 80cm (about 32 inches) deep! That's some serious deep leaf litter! Especially considering an average water depth of 49cm (about 19 inches)! That's a very interesting "substrate-to-water-column ratio", wouldn't you say? And the interesting thing is that, while there is some seasonal variance in the water depth of the habitat (about 15cm/6inches) during wet and dry seasons, the leaf litter depth at most varied by about 6cm (2 inches) during the seasons. The pH of the water varied between 4.1-5.29 in these locales.

As one might imagine, areas of greater water depth yielded a greater number and variety of specimens.

Here is a grouping from one of the sample locations that is very representative of the types of fishes you'd find in such an environment:

Crenuchus spilurus

Nannostomus marginatus

Pyrrhulina brevis

Iguanodectes variatus

Hyphessobrycon sp.

Hemmigramus sp.

Aequidens pallidus

Apistogramma steindachneri

Rivulus compressus

Obviously, not all of these species will be easily available at any given time, so you can, of course. "fudge it" a bit and throw in some similar species, such as other Rivulus or Apistos as need be, without changing the "flavor" of the community, right? 

That's an interesting, primarily "characin-dominated" community, wouldn't you say? If you notice, the assemblage includes shouting fishes, more "solitary" species, and fishes like the cichlids, which establish their own social hierarchies-as well as the Rivulus, which often aggregate in groups on the fringes of the slower-current pools of the igarapes in the study.

I could easily envision an interesting community of little fishes derived from this list, occupying all different strata of a botanical-influenced, blackwater aquarium. The neat thing here is that you have fishes with a variety of shapes, sizes, colors, and habits all in a relatively small area. (these were captured in 3 meter by 2 meter/27 x 6 ft seines, to give you some idea of the sizes of the areas from which the samples were taken). Now, that's obviously a lot larger than even the largest home aquarium, but the relative proximity and variety of fishes in the given area is interesting! I think we could obviously "compress" this a bit and utilize a more-or-less similar combination of fishes in a realistically-sized home aquarium with some good amount of success!

There is obviously so much more to creating a harmonious community of fishes than just mimicking a group found in one study and convincing yourself that you've created an amazing aquarium! You obviously need to take into account the size of your aquarium, and even more- the physical "structure" of the aquascape. As alluded to in an earlier guest blog by Mike Tuccinardi, the physical attributes of our aquascapes are not just aesthetic in nature; rather, they provide the basis for natural behaviors, interactions, and the overall comfort of the fishes. 

The open-water-shoaling Hyphessobrycon species need some space in which to swim, while the more "sedate" Crenuchus and Iguanodectes like to have some structures, such as driftwood or root tangles, to hide among. The cichlids are happiest with some access to the substrate, with other physical features, such as holly logs or large stones, in which to create spawning sites and establish territories.

The Rivulus like open areas of water surface, so that they may opportunistically feed on insects that fall into the water, and be able to (gulp) jump from pool to pool as the fish feel is necessary (obviously, a cover of some sort is necessary to discourage this "natural" behavior!).

By studying and considering various aspects of the natural environments and the aggregations of fishes which live in them, and interpreting and utilizing some or all of the information derived from them, it's very possible to create vibrant, compatible, and very functional aquarium systems! 

Just another component of the "functional" aspect of the botanical/blackwater aquarium which can be applied to a variety of aquarium keeping situations. We see this approach taken in African Rift Lake cichlid community aquariums, and such logical stocking approaches go beyond simple aesthetics, so we have hobby examples of the success of replicating natural community compositions from various locales worldwide in the aquarium. 

It's well worth our while to take some cues from "Mother Nature", the ultimate aquarist! 

Some fun stuff to consider on a Monday!

Until next time...

Stay relentless. Stay informed. Stay curious. Stay creative.

And Stay Wet.

Scott Fellman

Tannin Aquatics

Giving back...Playing our small part.

“If you wait until you can do everything for everybody, instead of something for somebody, you’ll end up not doing nothing for nobody.” ~ Malcom Bane

We take so much from the Amazon region in the hobby, materially, biologically, and creatively. Over our "fishy career", the habitats and fishes of this region have brought so much enjoyment and fascination to us.

We felt that it was time to give a little back to both the people and the environment of this region which has given us so much over the years. We at Tannin Aquatics, being inspired greatly by this amazing region of the world, want to do something, and we're hoping you'll support our efforts.

You may have not known this, but the indigenous peoples who populate the Amazon region in the municipality of Barcelos (Amazonas state, Brazil), earn most of their income from the home aquarium fishery! In fact, the trade in home aquarium fish now contributes at least 60% of the income revenues in the municipality.

That's amazing.

The annually inundated forest areas- such as the igapos- provide a huge bounty of fishes during productive years, and during these periods of inundation, the local fishers intensify their collection efforts for the aquarium trade.  As we've discussed before, many forest fishes have a short wild life cycle (less than 2 years), and fish populations can be quickly replenished. It may, therefore, be possible, through proper management, to protect the habitat from degradation, while maintaining “bountiful” harvests at the same time. 

There is sort of a double-edged sword in the aquatics industry: On one hand, we've gotten pretty good at commercially breeding many species of fishes found in this region. Advancements in aquaculture technology have enabled fish farmers to propagate dozens of species of fishes, and farmed stocks are replacing wild-caught fishes. In fact, it's estimated that about 90% of all home aquarium fishes are from farmed sources, and these are often not based in the countries of origin. 

On the other hand, although captive commercial propagation is very important, it also denies the indigenous people the benefits of the biodiversity from the region that they inhabit. To support their families, they would typically turn to logging and other potentially environmentally destructive industries to make ends meet. 

When fishers are asked what they would do if they could not sell fish, the most common answers are: timber harvest, cattle ranching, gold mining, or even urban migration. Was there a "happy medium" somewhere? 

It turns out, there is.

In 1989, researchers and students from the Universidade do Amazonas (UA) and National Institute of Amazon Research (INPA) initiated an ecological baseline study on floodplain fishes of mid-Rio Negro basin. Researchers discovered the importance of the home aquarium fisheries for local livelihoods and speculated about the environmental impact of fishing activity. Very early on it was discovered that the home aquarium fishery was not only sustainable, but it was the principal driver for creating value for the environment.

Two years later, in 1991, Project Piaba was founded with a grant awarded by CNPq (National Research Council of Brazil).  The ultimate goal of Project Piaba is to promote the collection of wild Amazonian fishes at commercially and ecologically sustainable levels, and to help to reduce environmentally destructive land use and rural-to-urban migration in the Rio Negro basin of the Amazon rainforest.

The mission: "The Mission of Project Piaba is to increase the environmental, animal welfare, and social sustainability of the Amazonian aquarium fish trade, to develop and incorporate metrics through which this progress can be assessed, and to provide mechanisms to promote this industry."

The organization's slogan,"Buy a Fish, Save a Tree" communicates precisely the aim and benefit here.

Project Piaba aims to generate data relating to a wide range of issues, ranging from population of species diversity, to the function and structure of the ecosystem. In addition, they seek to developing measures that will help improve the livelihood of the riverine people of Barcelos, Brazil. 

For more nearly 25 years, Project Piaba has been researching the home aquarium fishery of the Rio Negro. The organization trains and works with existing fisherfolk organizations and community groups on information exchange and efforts to alleviate poverty through a strong fish trade with benefits for local communities. In addition, working with the fishers, the organization has helped create "Best Handling Practices" protocols for fisherfolk to maximize animal welfare and trade value of fishes.

Project Piaba also works to inform and network with key groups that influence the aquarium trade, including the mainstream conservation community (e.g., Association of Zoos and Aquariums, Conservation International, International Union for the Conservation of Nature, etc), aquarium fish trade groups, large retailers, In-situ and Ex-situ trade regulators, and the hobbyist community.

As lovers of the Amazonian aquatic environment, we are completely supportive of the mission and goals of Project Piaba. We gain so much from this amazing place, and we consider it an honor to support efforts to protect and preserve this precious habitat and the livelihood of the peoples who live and work there. With its focus on creating sustainable economic stability for the local people and protecting the environment, supporting Project Piaba was a true "no brainer" for us!

How are we going to do it?

Well, to being with, we are going to be offering several cool new variety packs of botanicals, inspired by the region, from which a percentage of the profits will be donated directly to Project Piaba. The first pack, "Bela Igapo" , is available now, and we will be adding several more packs and items at various price points, from which donations will be made. Our goal is to ultimately have an entire section of our website devoted to items which will benefit Project Piaba; we'll be gradually rolling them out in the coming months!

Another exciting item we'll be offering are some hand-carved wooden art pieces, made by the fisherfolk themselves, representing the fauna of the region. Some will be sold separately, and others will be included with some of the botanical packs we'll be offering! By purchasing these unique art pieces for yourself or as gifts, you'll be supporting the continuous efforts of Project Piaba to create a lasting and sustainable fishery for the indigenous fisherfolk of Amazonia.

And, farther down the line, there just might be some more very exciting offerings from Tannin that will support this awesome organization! You'll just have to stay tuned! In the mean time, I hope you join me in supporting a very worthwhile cause, which will have lasting positive impact on the environment, our hobby, the people of Amazonia, and most important, the fishes.

Stay involved. Stay engaged. Stay supportive. 

And Stay Wet.

Scott Fellman

Tannin Aquatics 

(Special thanks to Mike Tuccinardi for his pics, and Deb Joyce of Project Piaba for her enthusiastic support of our efforts!)

The opening act...

I've written and spoken about this idea before, as no doubt many of you have: Pre-colonizing your aquarium with beneficial life forms BEFORE you ever think of adding fishes to it, and establishing a "functional" hardscape environment at the same time. A way to sort of get the system "broken in", with a functioning little food web and nutrient export crew in place. A chance for the life forms that would otherwise likely fall prey to the fishes to get a "foothold" and multiply.

Now, this is not a totally alien concept to me; I've done it several times with reef aquariums with great results. Earlier this decade, I maintained a seagrass biotope aquarium, complete with Pipefishes, Dragonets, and other rather touchy fishes, and I was committed to getting the system "populated" with amphipods, copepods, and other small crustaceans, to help serve as supplemental food sources for these rather difficult-to-feed fishes. It was a very, very successful tank for a number of years!

The same idea works great in a blackwater, botanical-influenced aquarium. It's very much along the lines of some of the ideas we've talked about lately. You set up your aquarium, complete with some botanicals, leaves, and wood, and add cultures of animals like Gammarus, Daphnia, etc., and let them go to work on the decomposing leaves, etc. The hard party is....waiting. Yeah, waiting to add ANY fishes for around a month or so, to really give the animals present a chance to settle in and reproduce. Trust me, it's not as easy as you might think. You've spent all of this money on a cool idea for an aquarium; you're ready to go...and then you're looking at a dark tank with the occasional Daphnia sighting.

Wow. Crazy. Okay, I hear the groaning already...

It's that hardcore a thing. Not easy, but totally doable if you're the patient type. And the rewards are supplemental foods galore for your more delicate fishes! And, on top of that, you have an aquarium habitat that is "richer", more complete than one in which you simply toss in the fish after cycling.

I am also a firm believer in the idea of utilizing pieces of wood, rocks, even substrate from established, healthy aquariums in new tanks. Always have been. Again, for the same reason- you're taking what amounts to a sterile box and tossing in "dry ingredients", and then some fishes...so where is the biodiversity? 

Remember, we're not just about an aesthetic here! Where is the food web? Where is the "functionality" of the system? These things form over time, but from day one, you have a box filled with rocks, sand. leaves, and wood. We can do better, right?

As we talked about previously, the idea of "starting" your aquarium before you actually start the aquarium is a pretty good methodology. And it need not be a long, boring process. Getting the tank "set" and "primed" for fishes can be as exciting and dynamic as any other point in the process. Getting the stage set for microbial, fungal, and crustacean life forms is actually pretty interesting.And it's sort of an "intro" to the whole "lifetime management" of this type of aquarium, anyways! Remember, botanical-style, blackwater aquariums are dynamic, actively-manageable systems that are remarkable in their "evolutionary processes."

And, one could conceivably stock the aquarium with botanicals in a sort of progressive manner, too. What do I mean? Well, for instance, you could start your botanical tank with a rich soil-and-botanical-influecned substrate material, gradually increase the water level over a few days, add a piece of driftwood, and some of the more durable seed pods and other botanicals  you intend to add (i.e.; "Savu Pods", "Jungle Pods", Lampada Pods, "Ceu Fruta", etc.). Let them sort of "age" for a week, and then add some of the less durable pods, like "Rio Fruta", "Coco Curls", "Terra Sorrindo", etc.  This is where I'd add the various small crustaceans, if you have access to them.

Wait another week. Add your leaves- the less durable ones first, over the course of that third week. So your sequence would look something like this: Catappa, Loquat, Guava, Jackfruit, Magnolia. The ones that are starting to soften and impart their tannins to the water will be supplemented by the longer lasting Magnolia and Guava leaves. And you're cycling your tank via whatever your other favored method is at this point. 

So, before you've ever even added single fish to the system, it's "tinted", the pH is more or less stabilized within a range, there are some crustaceans "in play", biofilms have started forming, and the system acquires a more "aged" look, from an aesthetic standpoint. And, you can "edit" as you see fit, adding more leaves, removing or adding botanicals, etc.- just generally beginning the process of "operating" your botanical-style, blackwater aquarium. Its a dynamic, ever changing, constantly-evolving aquarium system.

Now, this sequence-this "dance"- isn't for everyone. In fact, most of you will not do this. Many of you will say, "Why bother?"  And that's okay; you run your system in a manner that works for YOU. However, if you're the supremely patient type, and want to really study and observe and relish every aspect of the startup of your aquarium, a sequence similar to the one presented above is pretty cool! The opportunity to learn and advance the state of the art by doing this is almost irresistible to some of us!

And you can throw all sorts of variations into the mix, once your tank gets going, if you want: "Seasons", created by light and water level/flow manipulations, "leaf surges" (adding a larger quantity of one type of leaf in a shorter period of time, or a smaller quantity  for a protracted length of time, to simulate seasonal "leaf drop" from forest trees), food surges, stepped-up water changes, nice-oriented fish-stocking sequences, slightly increasing substrate depth and varying its composition, etc.

All of these processes rather elegantly (or crudely, I suppose one could say) mimic some of the things that happen in nature as the "rainy season" or "dry season", as the case may be- progress. You could conceivably start your tank in the igarape/igapo "dry season"- or vice versa- and progress it from there! Each one of these manipulations has multiple implications, benefits, consequences, influences, and lessons to be learned. Any one of them can be a key factor in the successful husbandry of a number of fishes...we just need to try!

Nature gives us all of the ideas and inspiration we need. We just have to look at it and think beyond what we typically do in managing the "startup" and operation of the aquarium.

Managing a botanical aquarium at every phase offers opportunities, challenges, and educational experiences that we can use to push the state of the art of botanical, blackwater aquariums- and to add to the growing body of aquarium knowledge about managing these unique systems over the long term. And sharing your experiences- good and bad- will provide those who follow with more confidence to follow in your footsteps, creating their own aquariums, pushing the limits in their own way- and growing the global "tint community"- and aquarium hobby in general- through their efforts.

All good. And it all starts with a carefully thought out, well-orchestrated "opening act."

Get started. Enjoy the process. At every stage.

Stay focused. Stay engaged. Stay excited. Stay enthusiastic.

And Stay Wet.

Scott Fellman                                             

Tannin Aquatics 

Variations on a theme...experiments with Epiplatys annulatus and the idea of going beyond the ordinary...

I love killifishes.

Have you ever thought of keeping killifishes in a setting that is more similar to what they're found among in the wild? Now, I know that for controlled breeding, you'd typically want to keep them in small, bare tanks, with spawning mops, peat moss, or whatever the appropriate substrate is.

However, what about trying to simulate the habitats in which some are found? Would this work? Could you do it effectively? Would the fish reproduce?

Well, first off, I have no illusion that you'll be able to produce as many fishes as often as in a controlled, more "artificial"-type spawning setup. However, as one who is fascinated by how fishes interact with their environments, I couldn't help but wonder you could at least create an interesting, if not viable, setup to more realistically simulate the natural habitats from which these fishes come from. Oh, and I realize that we've been doing the "permanent setup" thing with killies for decades- you know, a small tank with a dense coverage of plants. That sort of thing. Now, that works, and may very well simulate the habitats of some killies, but many come from habitats which we generally don't replicate in aquariums. Habitats that lend themselves well to experiments on a very small scale!

Examples? Well, let's look at the tiny, but surprisingly popular Epiplatys annulatus Monroviae, "The Clown Killie." This little fish is commonly kept in the aforementioned permanent setups with a fair degreee of reproductive success. Of course, you can't argue with the success, but you can think about creating more natural conditions for these fishes to see if you'd get any different results, right?

Yeah.

Over the years, I chose this rather "touchy" species as my muse, along with the much easier to keep Epiplatys dageti Monroviae, as my killie of choice. I spent a lot of time studying the wild collection areas of these fishes, and came up with all sorts of ideas and theories about every aspect of them, ranging from why they have the colors they do, to what they really eat in the wild, to, what kind of water conditions to keep them in.

So, for the most part, these fishes are often found in very shallow jungle streams. How shallow? Well, reports I've seen have stated that they're as shallow as 2 inches (5.08cm). That's really shallow. Seriously shallow! And, quite frankly, I'd call that more of a "rivulet" than a stream! Virtually still, with a barely perceptible current. Now, I don't expect you to set up a tank that's 2 inches deep...but what about like 3.5"-4" (8.89-10.16cm) deep? Totally doable. There are some pretty small commercial aquariums that aren't much deeper than 8" (20.32cm), and you could adapt other containers for this purpose, right? Like storage boxes, etc. That's like "standard-issue" killie stuff.

However, we're not content to simply set up a 4-inch deep tank, throw in some killies and a clump of Water Sprite and call it a day, right? Nope. We need to do better. Let's think about this habitat again for a quick second.

As mentioned above, these little jungle streams are really shallow, cutting gently through accumulations of leaves and forest debris.  The great killie documenter/collector, Jorgen Scheel, precisely described the water conditions found in their habitat  as "...rather hot, shallow, usually stagnant & probably soft & acid." Ah-ah! We know this territory pretty well, right?

Oh, and here's a cool fact you may not have thought about...keep this in mind:  Because they also inhabit coastal areas (mine were the "Monroviae" population...) they are also found in slightly brackish water!

Hello. Yeah... And yes, I've exploited this interesting fact in the past, conducting a few experiments with this species as we'll see shortly- with really good results, too! And hopefully, you will too, in the near future, when we start releasing the Estuary line of stuff...but imagine, a botanical-influenced, brackish-water aquarium? For killies? Yeah. 

Ahh...back to the idea at hand....

How about a long, low aquarium, like the ADA "Cube Garden 60F", which has dimensions of 24"x12"x7" (60x30x18cm)? You would only fill this tank to a depth of around 5 inches ( 12.7cm) at the most.

Here is a pic of my experimental brackish water Epiplatys annulatus setup from a few years back. This one I actually filled to the top, used a fine layer of fine, white sand, and kept the water very slightly brackish (s.g.1.003). It was kind of an odd dichotomy, really, because I used some botanical items in the sort of "island" of rock I created in the lower light area on one side. You can guess where the fish spent most of their time! I incorporated what I now call "Mariposa Pods" a few little "Savu Pods", and some Coco Curls into the "island", which had a mix of terrestrial and true aquatic plants. Kind of a dichiotomy, because I had a "planted brackish botanical tank", with slightly tinted water!  Yeah, I've always liked pushing in different directions! 

Just a hint of salt...

Bet you didn't know this:

There almost was no Tannin Aquatics. Well, not right away, anyhow.

Yup, before we launched the "brown obsession", as one of my friends calls it, there was my other project...

You see, as an obsessed reef aquarist and co-owner of one of the top coral propagation/vendor facilities in the U.S.,  it seemed like a transition from marine to specialty freshwater would be a tough one, even though blackwater aquariums were an obsession for over 25 years. Just going "cold turkey" into full-strength freshwater seemed like a tough road.

There was this other lifelong obsession of mine, which seemed to my friends to be a more logical transition for a geeky aquatics entrepreneur...

Brackish. 

Yeah, brackish.

I had kept brackish tanks for years...a natural compliment to reef tanks; and, at the time, it seemed a good way to transition from the coral world, at least! The "Tannin thing" would come later, a natural "digression" from salt-sequentially, if you will. Brackish made sense for someone who had his head firmly in the saltwater world for decades. I mean, it wasn't going "all the way" fresh, so it wouldn't have to "wean myself" with as much effort. I developed a brand, product ideas, and all the trappings you'd expect from someone who is totally into something. 

Then I stopped it. Cold.

I wanted to make such a radical departure from reefs, and loved the nuances and aesthetic of blackwater so much that I just couldn't wait. Tannin won out. The "brackish thing" now became my "side project." Called "estuary" (named after the most extensive brackish water habitat globally), this idea would be developed over the longer term, while Tannin was bursting onto the scene. It would eventually become a specialty line of Tannin, and it would have to wait.

I was ruminating a couple of weeks ago with a good fish friend about the idea of brackish water aquariums..and why we see so little in the way of brackish water aquariums. 

It's almost like an aquarium hobby "no man's land." A mysterious middle ground that everyone knows about, but one which aquarists rarely seem to go to...

Unusual. Under-served. Flying under the radar. Rampant with incomplete ideas, myths, false assertions by those who had never even tried it... Hmm, this situation is sounding a bit familiar...

I mean, on one side, we have FW purists, and on the other, marine purists. The two never seem to meet. Unless you count African Rift Lakes as a sort of "in between..." 

Nah.

Sure, you have people who keep puffers, mollies, etc.- some of which are found naturally in brackish water, but you won’t generally hear this people intimating that they are “brackish water enthusiasts.” They’ll say, “I keep Puffers.” or “I breed wild Mollies.”

I guess the whole classification of “brackish” may seem too "limiting" for our tastes? Like "blackwater aquariums", it’s just a label, but I suppose we tend to think more about the specific animals we keep than the type of aquarium system that we keep them in. At Tannin, it seems like we're constantly pushing “biotope-type aquariums” as a specialty unto themselves, when the reality is that many of our customers breed, say, cichlids, livebearers, or catfishes, which require-(and are furnished) specific conditions (essentially "biotopic" in nature), yet when pressed, these hobbyists will definitely classify themselves as “cichlid breeders” or “catfish enthusiasts”, etc.

Well, until recently, when you now have hobbyists calling themselves "tinters" or "blackwater aquarium enthusiasts." 

Yeah.

And the brackish world? 

Well, some of us are already there...sort of.

For some reason, "brackish" seems to be a lot like "blackwater"- one of those mysterious and under-appreciated "specialty areas" in aquarium-keeping. It certainly is kind of sad to not see more aquariums in the spotlight that focus on this unique and fascinating specialty. I think a lot of cool work could be done in this area by the many talented aquarists out there- fresh and salt.

(And yeah...the Amazon has an estuary area. too...)

I hate seeing good ideas that deserve more attention being neglected.

We just don't see much going on in the brackish "arena" at the moment.

Does it matter?

Probably not.  

Well, to me it does. And, think about it…When was the last time you saw a really cool full-blown brackish water aquarium, community or otherwise, done up with style and the same “cool factor” that we see with say, planted FW aquariums, reef aquariums, or more recently, botanical/blackwater tanks?  Okay, George Farmer did an amazing one in a piece featured in Practical Fishkeeping not too long ago...I know there are a few others around; many may even fall under “unusual” or "concept" aquariums…the kinds that come out in aquascaping contests and elicit a lot of “That’s so cool!” -type responses on the forums and such, and then no one really does much with them after that.

Damn, this sounds so familiar that it's not even funny.

Perhaps, in our minds, we think that fish and plant selections are too limited because of the environmental parameters? Not sure. Seems like there are a ton of cool fishes, besides just the aforementioned Mollies and Puffers, that can inhabit a nicely done brackish water display!  I've played with some fishes, plants, and ideas in the brackish field that blew me away.  And those fishes? More are available when we do the research. Thanks to a lot of dedicated hobbyists and industry types, "rare" or "difficult to obtain" fishes really aren't any more.  You just have to look..and ask.

And the environment for these fishes? Is it tough to maintain? 

A specific gravity of 1.003-1.010 is not really all that difficult to maintain, and most brackish water fishes, often coming from areas affected by tidal influxes, tolerate fluctuations quite well, making them rather forgiving. Refractometers become your friends in the brackish game. And the synthetic salt mixes we have nowadays blow away anything ever available in decades past. And as far as the hardiness of the fishes themselves? I think the species labeled as "delicate" for so long acquired that label because frankly, we weren't providing them with proper conditions. Sure they did "okay", but they weren't "thriving" in many cases. Keeping fishes from special environmental niches requires some attention to details, as we all know.

And there are a LOT of interesting fishes that fall into the brackish water category- For example, the Orange Chromide Cichlid, Etroplus maculatus, the Celebes Rainbow Fish, Marosatharina ladigesi, the "Archerfish", Toxotes sp., and so many, many more. Those are just the cliched' "commonly-known" ones. There are also gobies, killies, Monos, Rainbowfishes, Scats, all kinds of livebearers, etc., etc. 

This discussion is more about considering the concept and philosophy of brackish water, rather than going into detail about what fishes and plants to keep and how to build one, so I’m merely touching on a few ideas here. We will hit details in later features as things move along.

Although in nature, plants are not abundant in brackish water habitats, you can keep plants in brackish. Not the crazy variety that you can in pure freshwater, yet you can choose from species among several popular genera in lower specific gravities (up to 1.003 or so): Anubias, Cabomba, Ceratophyllum, Elodea, Java Ferns, even Cryptocoryne cilata, and Hygrophila, to name a few. When you get to 1.005 or above, the choices become fewer and farther between.

Yeah, and there's Mangroves. I love Mangroves. Reefers have been playing with them for decades. Aquarists have some good experience with them. What plant could be better for a brackish tank?

At the higher specific gravities (above 1.005), you'd be better advised to go with a hardscape, featuring wood, rocks, shells, etc. Mangroves, of course, can adapt to this specific gravity, but the hardscape might be more appealing to many for ease of maintenance. Hmm, maybe even with some of the less "tint-inducing" botanicals as well...?

And we can utilize many of the skills, practices, and equipment that we've embraced in freshwater, reef or Rift Lake cichlid husbandry to keep brackish systems. Top-off systems to maintain specific gravity, water chemistry tests, amazingly good syntehtic salt mixes, precision heaters and pumps- all of these things are near perfect for use in brackish systems. It's no longer just "a teaspoon of salt per gallon" and "vigorous aeration.."- you know, that kind of stuff.

It's a whole new game.

I just feel like there is so much talent in the aquarium hobby, and equipment, livestock, and information about these habitats has never been easier to acquire, that I'd love to see some more work being done in this arena, other than just providing these conditions for the several random fishes that we occasionally work with…In other words, keeping a brackish tank…just because it's fun.

The timing is so right.

And that's why we're going to be launching "estuary by Tannin Aquatics"  as a "boutique" on our site soon. We're going to apply the same level of obsessive detail to the brackish world as we do to the blackwater/botanical area. You'll find products, ideas, and inspiration for this unique niche all in the same place you get "The Tint."

It's time. 

Bottom line is that the brackish aquarium is one of those unique niche systems that, at least in my opinion, deserves a lot more than just the passing mention in hobby literature, and a lot more attention from intrepid hobbyists itching to try something new. It needs some "fresh" (no pun intended) thinking and outside-the-box ideas. Very similar to the world of blackwater/botanical aquariums that we have started to see more and more of.

Brackish water is a fascinating, engaging environment that, if explored with the attention that it commands, can unlock further secrets of fish husbandry, and a greater appreciation for this precious habitat.

Until next time…

 Stay interested. Stay obsessive. Stay open to new ideas...

And stay wet. (Salty, fresh..or brackish, for that matter!)

Scott Fellman

Tannin Aquatics

Beneath the substrate...another component of "functional diversity" for the botanical aquarium...

Yesterday afternoon, I was busy engaging in that most enjoyable seasonal activity- clearing out our little vegetable garden to get it ready for the upcoming season. There's something nice and a bit relaxing about working in your garden, isn't there? And I think it's the same feeling many of us get when playing with our aquariums. Something about the soil itself that does it for me...

We definitely look at our aquariums as "gardens" of sorts, right? And gardens contain more than we perceive on our initial view, right?

What caught my interest as I was turning over the soil and removing some of the roots and remains of last year's plants was the large number of worms and insects that "work the soil" over, keeping it aerated and rich. Of course, being a fish geek, I kept thinking that there was some analogy to what we see in aquatic substrates. But the reality hit me that we typically don't cultivate anything more than "beneficial bacteria" in our aquarium substrates.

And of course, I had to give it some more thought. In reef aquariums, we are really into things like various worms which inhabit sandbeds. They're seen as part of a vital ecosystem in the reef tank, helping to process excess food and nutrients, creating waste material which feeds the "next guys down" on the food chain, and generally keeping fine sand from compacting too much.

In the freshwater aquarium, we seldom hear or even discuss such life forms, let alone, culture any for our aquariums. And what's weird is that I can't really think of any reason why we wouldn't want to...I mean, they're not going to eat your fishes, uproot your plants, or out-compete your Loricariids, Corydoras, etc. for food down there.

Is this another one of those "because it's not done that way" kid of things; some practice or belief rooted in both "tradition" and a bit of fear over trying something new? Or concern that, because you acknowledge that there is  enough "food" down in the substrate to support life, that your tank is "improperly maintained?"

Hmm...

And, since we are seeing more and more "rich, botanical-influenced" substrates appearing in our aquariums, as in our friend JT martin's tank below, you'd think that this would be an appropriate time to experiment with some of these  creatures in our tanks. I can see a lot of benefit to having some organisms in our systems which can help process the decomposing materials from pods and leaves, very similar to what occurs in nature in leaf litter beds. And, one could imagine that, just like in nature- there is a significant benefit to having them in the system as a supplemental food source- again, just like in nature. 

I guess the difficult part would be to obtain some of the insects, crustaceans, and worms that inhabit aquatic substrates. A good starting point might be to start with some crustaceans such as the reasonably easy to obtain Gammarus. This is a genus with over 200 species, many of which are found in exclusively freshwater habitats, and are commonly available as "life food" cultures.

Here's where it gets kind of interesting. They tend to feed on and among "allochthonous organic matter" (i.e.; leaves, wood, and botanical items) in streams and rivers. Freshly fallen leaves and other plant detritus that enter the water are rapidly colonized by microorganisms and fungi, and the Gammarus act as  "shredders", which feed on the leaves and on detritus that has been previously colonized by fungi. And your fish will munch on the occasional careless Gammarus that slips through the leaf litter...Hello, food chain.

And since we're all about leaf litter and botanicals in our aquariums, and studying the natural processes which occur there, this might be as good time as any to take an even closer look at how wild leaf litter beds function in nature, and how we can at least superficially replicate the process that occur within them.

Other possibilities for our initial foray into the world of substrate-dwelling aquatic organisms could be worms...like the Tubifex worms, or the so-called "Black Worms" (Lumbriculus variegatus) which are common to the trade. 

These worms inhabit aquatic environments, such as pods, swamps, and streams, and spend most of their time sifting through substrate and  feeding on microorganisms and  and organic material. And of course, our topical fishes LOVE them! SO, would there not be some benefit to having them inhabit your enriched substrate, "doing there thing" and providing the occasional "snack" for lucky fishes? Yeah....

Our friend Mike Bognich is experimenting with just such a setup in on of his experimental leaf-litter- bottom aquariums! A very cool idea that will benefit from more and more forward-thinking hobbyists playing around with it! 

And of course, in the wild, there are many other creatures which grow in the substrate/leaf litter beds, many of which we've never experimented with, or wouldn't want to (like larval stages of flying insects, mosquito larvae, etc.).

And of course, some are readily available, but are typically not animals you'd keep in aquariums, like Daphnia. Hello, refugium! 

Obviously, we're just literally scratching the surface here...There re numerous possible candidates for "in-aquarium" substrate dwellers, which would work well, not attack fishes, and which could perform a variety of roles in our tanks. As more and more of us look to nature for inspiration about substrates and litter beds and such, more and more focus will be paid to this seemingly neglected corner of aquarium study- and it's about time!

We are definitely looking forward to seeing more and more of you examine the more functional aspects of botanical-style/blackwater aquariums, and making meaningful and fascinating contributions to the aquarium hobby that will benefit others. Letting go of old beliefs and "rules", in search of answers, and unlocking secrets. 

Good stuff.

Stay curious. Stay experimental. Stay brave.

And Stay Wet.

Scott Fellman

Tannin Aquaitcs

The inherent beauty of subtlety

I have no idea why, but I'm definitely one of those guys who loves grey and brown fishes...

Yeah, seriously... 

When I consider new fishes for my tanks, I'm not pouring over the selections either online or in person, looking for the brightest, most gaudily-colored fishes around. Nope, I'm obsessing over color patterns and intricacies. Subtle blends of tone and "texture."

I mean, even brown and gold and ball offer variations that are compelling, IMHO.

Now, don't get me wrong, I love really colorful ones, too- but for some reason, in recent years, my affections towards brown fishes has increased. I think it's in part because of my love of the blackwater, botanical-influneced aquarium I'm so obsessed with. One of my friends jokingly told me that he thinks it's because I grew up owning an old-school copy of William T. Innes' "Exotic Aquarium Fishes" that had nothing but black and white pics, and I obsessed over the patterns instead of the colors of the fishes...Hmm, he might be onto something there, as my favorite characin, Crenuchus spilurus, the rather subdued "Sailfin Tetra,"  is a strong childhood memory from the black-and-white pic in that book! 

All speculation aside, I think that there are some cool reasons to love the more subtly-colored fishes as primary "players" in your botanical, blackwater aquarium. The first and foremost is that they don't compete with the colors of the botanicals; rather, they compliment them. 

Having more subtle-colored fishes is far more engaging, to me. Having lots f brightly colored fishes swimming all over a bright, crisp-white tank is just...well- get a reef tank at that point! :)

And further, by creating a population of largely subtle-colored fishes, you create a sense of harmony and a relaxed aesthetic which sets the stage for the few brightly-colored fishes that you'd use, like Cardinal Tetras and Neon Tetras, etc. Sort of like in nature, where the really brightly colored fishes occur either in large schools, like the species mentioned above, or are just random individuals scattered throughout the leaf litter.

And isn't it kind of fun to "explore" your aquarium and have to do a little looking around to see what's swimming? I have always felt that many of the best aquariums I've ever encountered are not the ones with the most equsiite aquascape or most color full collection of fishes. Rather, to me, the most visually engaging aquariums are the ones that have intricate aquascapes with subtly-colored fishes throughout, inhabiting all sorts of niches within the tank. The brightly-colored ones are sort of the "icing on the cake", and add that pop of color that makes things dramatic and alive.

Interestingly, in talking with people who understand the way the colors of fishes is impacted by their environment, I was intrigued to discover that even the gaudy Neon Tetra is essentially a "stealth fish" in it's murky, blackwater environment, as far as ambush predators are concerned. Yeah- think about it. The red is virtually invisible in the dark, light-limited blackwater habitat, and the neon blue stripe bands in with the sky when viewed from below...you know, the place you'd be if you were the kind of fish that was looking to munch on some Tetras for lunch...

Interesting. 

And of course, the subtle, brownish-grey fishes with interesting patterns sort of blend right in, don't they? That's kind of cool, I think!

So, if you're thinking of stocking your next blackwater aquarium, I'd highly recommend going "subtle" for a while. Not only will you gain an appreciation of the way the fishes blend in-and yes, enhance- the aquascape, you'll be surprisingly pleased with the little intricate nuances of their color patterns. You'll develop a new appreciation for how and why these fishes evolved over eons, adapting to the complex, varied nature of their environment. Loud and bright is too easy...kind of overrated, in my opinion...

A favorite quote from author Neal Stephenson comes to mind...Although a bit aggressively satirical in its tone, there is a serious element of truth to it:

"The difference between stupid and intelligent people - and this is true whether or not they are well-educated - is that intelligent people can handle subtlety."

Ouch!

Don't overlook subtlety.

Today's simple thought for all you "tinters" out there.

Stay observant. Stay intrigued. Stay engaged

And Stay Wet.

Scott Fellman

Tannin Aquatics 

Technological "crossovers" from reef keeping that can up your freshwater game!

One of the things I find both interesting and frustrating as a reefer was all the gear that we tend to use to do stuff that you'd think could be accomplished naturally in an appropriately-designed system: You know, stuff like sulphur denigrators, algae light reactors, etc., etc.

Now, I dig these gadgets, so don't get me wrong...and apparently, so does the reef keeping world, as there is no shortage of fancy gear released every month to accomplish many of the tasks that nature is supposed to! And I can't help but wonder, as we explore more naturally-functioning systems, if some of these ideas and pieces of equipment are adaptable to our purposes. Let's look at a few examples of items that might have "crossover" potential.

FLUIDIZED REACTORS: I think these are terrific for all aquariums. They essentially consist of an acrylic tube, filled with filter media (typically activated carbon or phosphate-removing media) into which water from the aquarium is fed from the bottom of the reactor up through the media and back out into the aquarium. The upward water flow tumbles the media around  more-or-less-evenly inside the reactor, which permits greater contact between your the aquarium water and the media.

Now, what comes to mind immediately for me is to utilize botanicals, such as Alder, Birch, or Casuarina cones, in such a reactor, having them gently tumbled around, imparting their tannins into the water column and returned to the display aquarium. We tried this in the Innovative Marine "MiniMax" fluidized reactor that we offer on our site, and it worked great! There are numerous other reactors on the market that may be used similarly.  This application is perfect for those people who, for some reason, want the tinted water and humic substances imparted by the botanicals, but don't want these items in the display itself.

Are there other uses for fluidized reactors? Yeah, I think their could be some interesting applications for cultivating food sources, like Daphnia, for example. With a gentle flow, good light, and an occasional food input, I wonder if productive remote colonies of Daphnia, Cyclops, or other aquatic crustaceans could be reliably cultured and automatically distributed into the aquarium via the reactor? Hmm.

What about making a "peat filter" or "leaf filter" out of one of these reactors? Depending upon the flow rate within the reactor, and the size of the reactor, I would think it would be possible to have enough contact time with a lot of media to impart some dentritifcation to the system, in addition to the tannins? Maybe a finer-sized material, such as our "Mixed Leaf Media" or "Fundo Tropical" could do the trick? It's probably a fine line between creating something potentially useful, or making a "hydrogen sulfide reactor", but hey- isn't that what life on "the bleeding edge" is all about?

THE REFUGIUM: We've talked about this before...Absolutely a useful concept used for decades in the reef hobby, yet somewhat out of favor currently, during the more "focused" era of coral growth versus "ecosystem development", but very, very useful! A refugium is essentially a small aquarium, set up to receive water from the display tank. It's history purpose has been to provide- literally- a refuge- for delicate animals, macro algae, or "food organisms", like copepods, amphipods, etc.  For our botanical aquairums, there are numerous possibilities, including a way to grow rooted plants under intense lighting for nutrient export, the cultivation of ornamental shrimp that would otherwise be eaten, or to provide the botanical influence in an aquarium where a layer of leaves and such is not desired in the display.

Other possibilities would be to create a "remote deep leaf litter bed." This idea was suggested by John, one of our readers the other day, and I think it's brilliant! We talked about how fermentation that takes place in deep leaf litter beds in the wild contributes to a stable lower pH, and possibly to dentrification. A refugium might be an interesting starting point to experiment with? Completely filling a refugium with leaves could prove interesting! Now, I suppose if you pack leaves in too tightly, and have water flowing too slowly, the potential exists to create a large amount of hydrogen sulfide, so experimentation and caution are required when pursuing this idea. Who's up for it?

The refugium has numerous other applications, many of which we still need to experiment with. What about using it for a remote, soil-based "enrichment system", in which a reasonably deep bed (like 6"/ 15.24cm) or so is employed, perhaps with a mix of acidic soil types, peat, etc. You could create and experiment remotely with various combinations to mimic the soil compositions found in blackwater igapó, and the more alluvial-based materials found in the counterpart "whitewater" systems called várzea. I would imagine that some floating aquatic plants and some terrestrials could help with nutrient export in such a configuration...

The nice thing about a refugium is that you can take it "off line" if your experiment isn't working, or if you're having some issues...or simply if you want to run some "controls"  on the setup. A lot of flexibility, and a lot of possibilities here.

You could even use a large enough refugium to prep wood? You know, those big pieces that won't stay down. Most wood, like Mopani, etc., gives off a lot of tannins during its "prep" process, so why not take advantage of this and soak the wood in a refugium attached to your display aquarium, or multiple aquariums? And, wouldn't a big old piece of wood in a refugium function much as "live rock" does in a reef tank, fostering biocover and interstitial fauna which can benefit the display? So, like a "driftwood refugium?" Yeah...cool!

With reverse daylight run in the refugium, you could conceivably counteract any day/nigh pH fluctuation, especially of you active;y grow plants or algae "down there." A lot of possibilities. You could even conceivably construct a "paludarium refugium", with a mix of terrestrial plants and aquatics in a partially submerged state, directing some water to the "land" and allowing it to "percolate" back into the water...I mean, endless possibilities for creative aquarists who are willing to try something a bit different to test out ideas about replicating things that occur in nature... Wow!

ARID REACTOR: The other piece of equipment that reefers are starting to use is the ARID reactor from a company called Pax Bellum. The acronym stands for "Algae Remediation Illuminated Device", and that's exactly what it is! This is a new twist on the old reef idea of culturing macroalage for nutrient export. Essentially, the ARID is a "typical" reactor-shaped vessel into which water from the display aquarium is distributed. The "magic" of this reactor is a central "light pole" of waterproofed LED's inside of the light-colored reaction chamber, which provides intense light to the macro algae growing inside. What makes this system unique is the ability it gives you to just slam macroalage with nutritious lighting and water from the display tank. 

When I co-owned Unique Corals, we had the opportunity to play with some of the first commercial versions of these reactors in one of the coral grow-out systems in our facility before we offered them for sale, utilizing the beloved marine macroalage, Chaetomorpha, and the result were awesome! Author/aquarist Jake Adams of the popular Reef Builders blog  (his pics, btw) ran some tests with them at our facility, and we were very impressed with their capability to grow this stuff! This was right about the time I was launching Tannin Aquatics, and my mind wandered off to the possibilities of utilizing this device in a freshwater setting!

Now, in a freshwater application, I can see a lot of possibilities. Certain plants that require high light levels, which may not need to be rooted, for example, would do well in such a reactor. Mosses immediately come to mind, but the intense light may not work with many of them. Experimentation would be required! Now, I would be hesitant to utilize a planted reactor like this in a low-pH, blackwater/botanical system, because the high respiration rate of the plants caused by the intense lighting could raise your pH to levels that you may not want...So, a bunch of potential issues here, particularly if you're trying to keep a very low pH system. On the other hand, what if you're trying to keep African Rift Lake cichlids, which love the high pH and could benefit from the incredible nutrient export potential and pH support capabilities of this reactor? Hello.

I see lots of potentially interesting applications for the ARID reactor in the freshwater game, including the ability to cultivate some (pricy) high-light loving aquatic plants quickly- perfect for commercial aquatic plant growers who want to do some experimentation. The door is wide open. These are not cheap devices, but the potential for incredible results is there.

Obviously, there are many other devices targeted at the marine/reef hobby sector which we as advanced, progressive freshwater hobbyists can utilize in our systems. These are just a few of the ones that come to mind at the moment, but we've talked previously about the many internal pumps, controllers, and other gear that has "crossover potential" for our work. If you have a hunch, the financial means (lol), and an urge to try something a bit out of the ordinary, go for it and apply one of these pieces of reef tech to your freshwater "game!"

Stay inventive. Stay progressive. Stay fearless. Stay well-financed!

And Stay Wet.

Scott Fellman

Tannin Aquatics 

Blackwater "on the down low"- lessons to learn and repeat...

It seems like the deeper we delve into the blackwater, botanical aquarium world, the more ideas we get from nature, the more questions we have, and the more things we discover that are worth considering for our "practice." 

For example, the extremely low pH environments from which blackwater fishes come from are a very demanding environment, not to be taken lightly. However, our fear of very low pH aquariums is probably largely grounded in concerns over fluctuations in the parameters, and the challenges of maintaining consistent environmental conditions. 

Now, I'll agree, going into extremely acidic pH ranges is something we as a hobby have not had tremendous experience with, yet I get that nagging feeling in the back of my head that at least part of our fears may be unjustified. I mean, we've already discussed that ammonia at lower pH levels is not toxic. This, I feel, is where the bulk of the "mainstream hobby freak out" against our blackwater/low pH tanks stems from, so it deserves another look. As hobbyists, we should understand what we call "TAN"- or "total ammonia nitrogen." Our hobby test kits measure both ammonia (NH3) and ammonium (NH4+, also called "ionized ammonia"), which comprise "TAN."  This has important implications for those of us who maintain a low pH system ( like, below 6.0).

We need to be careful in managing our low pH, blackwater aquariums- particularly when performing water changes. Here's why:  Low pH can have a detrimental affect on the population of nitrifying bacteria that converts ammonia to nitrite.  Because of the acidity  of the water, these bacteria populations can drop so low that the "total ammonia nitrogen" (TAN) level can rise quickly.  No cause to freak out, because if the pH stays low the TAN level is pretty much all ammonium (NH4+), which is the essentially "nontoxic" ("gulp" for saying that!) component of TAN.  (To make you feel better, ammonium, even at high concentrations, doesn't kill fishes!)

If you do water exchanges with lots of alkalinity buffer added to the makeup water, the pH goes up, right? And what happens at a higher pH level? You guessed it:   The "non-toxic" ammonium can be quickly converted to very toxic ammonia, potentially causing ammonia poisoning to your fishes. I will hazard a guess that this is where many hobbyists have screwed up, and that many the "anomalous deaths" in otherwise "well maintained" low pH tanks were caused by this situation...and that further added to the "lore" that suggests that low pH, blackwater-type aquariums are bad news!  Key takeaway here: Keep things stable. If you're going to keep a low pH, KEEP it that way. Use water for exchanges that has pH values consistent with the water in your aquarium.

And that brings us back to...nature.

In studies of Amazonian blackwater environments, it was discovered that the pH in some areas was as low as 3.5...or less...and that these habitats had significant and rich populations of fishes. Now, the fishes have obviously evolved to thrive in these environments, so it's interesting to think about what makes 'em tick, as they say.

It's thought by some scientists that the humic acids from soils and botanicals that are abundant in these waters can only bring down pH so far. A current theory postulates that about 85% of the "work" in lowering pH in these waters is accomplished by the organic acids, and the remaining 15%...by CO2 fermentation taking place in deep leaf litter/botanical beds, perhaps producing stronger acids, like acetic acid. Further, the dominant decomposers in these extremely low pH environments (pH 2.8-3.5) are fungi, as opposed to bacteria.

Interesting.

Now, I am absolutely not suggesting that we attempt to achieve ph of 3.5 by packing a 20 gallon aquarium with 18 inches of leaf litter and letting it "ferment" in our tank...I can see the drama now. What I am suggesting is that we consider the fact that what we consider "low pH" for aquarium environments is not all that "radical." And further, that it's not terribly difficult to use RO/DI water to keep the low pH in a reasonably tight range in the aquarium. We need to understand the dynamics of the system...Reminds me a lot of saltwater or African Rift Lake cichlid systems...Understanding the "operating system" of the environment and working with it to keep stability and consistency.

Consistency.

The other interesting thing about these extremely acidic habitats from the studies I read were that the other parameters, like temperature, oxygen saturation, etc. were quite stable (oh, and not surprisingly, that the ionic content of the water was extremely low, as well). Again, stability within a range seems to be the predominant factor in the function of these environments, and this is a direct lesson for us as aquarists. It seems that no matter how "radical" the environment might seem to us, keeping the parameters stable wins out.

Although most of us are not too likely to explore extremely acidic pH levels in our aquariums, the lessons learned from nature on the function of these habitats can help us manage our "low pH" systems (like 6.5-4.9) much more effectively. There is still so much we don't know yet. We know that there are different types of bacteria and other microorganisms which take over for the more familiar Nitrosomanas and Nitrobacter at these lower pH ranges, and if it were possible to culture some of these organisms for use in filtration media for aquariums, can you imagine the impact for hobbyists who ply their trade in these waters?

I'm thinking Altum Angelfish guys, wild Discus keepers, etc.

Lots of possibilities here.

Like everything else, just contemplating these things leads to more questions than answers, but it shows you how much more there is for us as hobbyists to learn and understand, particularly from the wild habitats. Watching our fishes and observing OUR aquariums creates unique opportunities to break away from the dangerous "groupthink" that has, in my opinion, held the hobby back in recent years. Keeping an open mind and gently questioning "why" stuff is in our hobby will help us move beyond any previous restrains we have had.

Look, we will all make mistakes, go down some wrong directions, and possibly be extremely humbled by what we learn along the way. However, we'll be learning and doing- first hand- and not just accepting what is considered general hobby norms and practices "because."

Exciting times. Who's up for researching this stuff?

Stay excited. Stay curious. Stay relentless.

And Stay Wet.

Scott Fellman

Tannin Aquatics