Botanical aquarium husbandry basics...addressed again!

In this ever-evolving world of botanical-style, blackwater aquariums, there are a lot of questions about "best practices" and "how to's" which we see time and time again. Sooo... I thought, why not address a couple of the most common ones today?

What kinds of maintenance practices do you use in a blackwater/botanical-style aquarium? 

The key to ultimate long term success in the hobby at any level, IMHO, is not just having the ultimate system and the hottest equipment, as we've less-than subtly discussed many times- it’s the effort-the work- that you put in as a hobbyist to provide your animals with the best possible care. And the common thread seems to be that most of the successful hobbyists that I know share that basic philosophy.

And it all starts with that time-honored, yet oddly-reviled practice of regular water exchanges.

I'm stunned at the number of rather experienced hobbyists I know who simply aren't even close to consistent in performing water exchanges, yet complain about "problems" with their aquariums. It seems strange to even mention this, but it's a theme that has played out in a huge percentage of the "tank-decline nightmares" I've been called upon to troubleshoot over the past 10 years or so. Some hobbyists just don't want to do them, make excuses for not doing them, or just don't care...until the "shit hits the fan..."


The mind boggles. small water exchanges frequently.

Since the typical botanical-style/blackwater aquarium is set up with an initial "inventory" of leaves and other botanicals, we are accustomed to gradually "building up" the amount of these materials in our systems over a span of time. Patience! And, because of the very nature of botanical materials (they decompose underwater...), it is necessary to regularly replace them, much as you would filter pads, activated carbon or other chemical filtration media.

The act of replacing the decomposing leaves and botanicals not only mimics the processes which happen in nature (new materials being deposited into the waters), but it serves to continuously "refresh" or perpetuate the conditions within the aquarium. A sort of "mandatory husbandry process" that just happens to be the best way to maintain ANY type of aquarium for the long term, IMHO!

Fortunately, these materials are now more easily available to hobbyists than in years past! (In fact, we know a place...)

Much like in nature, the way you maintain your botanicals in your system can influence these things as well. There is a continuous and dynamic "evolution" that occurs throughout the existence of these aquariums, and the direction it goes is absolutely influenced by the degree to which we, as hobbyists are involved.

I think that the keys (from a maintenance standpoint) to really long-term success and stability of your blackwater/botanical-style aquarium are as follows:

1) Start slowly, gradually building up your quantities of botanical materials over a period of weeks or months, until you reach a level that you like aesthetically, and which provides the type of manageable environmental parameters you are comfortable with.

2) Employ basic, common-sense husbandry protocols, like the aforementioned weekly small water changes, careful feeding, use and replacement of chemical filtration media.

3) Stock your aquarium with fishes gradually, over a period of months, preferably with smaller fishes that can "grow with the aquarium" and produce less metabolic waste during the critical first few months as your system establishes itself.

4) Regularly monitor basic water parameters over the first couple of months to establish a "baseline" of how your aquarium functions and runs chemically. Continue this practice throughout the lifetime of the aquarium.

5) Regularly remove and/or replace decomposing botanicals (or NOT- depending upon your preference) with new ones, to help keep the same visual "tint" and consistent TDS/pH parameters.

6) Note any trends or deviations from the "baseline" over time and adjust as needed to stay within a fairly tight range.

That sort of covers the "maintenance thing" for today...Let's get to the #2 most commonly-asked question:

What do you do with the "prep water" after you've boiled, steeped or soaked your new leaves and botanicals?

We receive a lot of questions about this topic, and I always answer this honestly, based on my personal practices over the deuces with leaves and botanicals:

I use it to water the garden. It doesn't go into any of my aquairums.

Yes, I don't use the "tannin tea" as a sort of home-brewed "blackwater extract" in my aquariums. Why, you ask? Well, here is my "theory"- and it's really a theory, I admit...Although I think I'm right, I admit that I have no rigid scientific study to back it up:

Although most of our botanicals are fairly clean when we receive them from our suppliers, You need to remember that they are natural dried materials which fall from trees, etc. As such, they may contain in their surface tissues atmospheric pollutants and dust, etc. from laying on the forest floor or in the facilities of our suppliers, etc.. Is this stuff "toxic" in some way?

Unlikely, I suppose.

However, it's on or in the surface tissues of the botanicals and leaves, right? At the very least, we always say to rinse stuff before you add it, and then boil or soak. (Oh, the 'just add the leaves to your aquarium without boiling or steeping them" thing is something I've played with a lot over the years," just because"- and I admit I've never had a single problem. However, I will still never recommend that practice, for the reasons outlined above.)

The main reason we boil or steep our botanicals in boiling water is to break down some of the surface tissues of the leaves and botanicals, to make them more likely to absorb water and sink, and to realize and surface pollutants bound up in them. 

So, my theory is that your 'tea" does consist of a lot of good stuff- like tannins, humic substances, etc from the surface layers of the botanicals or leaves, AND it also contains whatever pollutants (dirt, etc. as mentioned above) that were present in these tissues as well. So, ask yourself: DO you want to add this stuff to your tank? I personally don't. Or, I should say, I personally don't want to take the chance of adding a solution of concentrated dirt to my tanks.

And what's the "dose" that you should use, anyways? Isn't it easier and far more natural to just add the botanicals themselves to your tanks, and let these materials leach into the water over time ("Yeah, Fellman...but at what amount?" Urrghhhh.)

Yeah, that's the old reefer in me...

Cautious in many ways, reckless in others. I remember lots of stupid "post conference" chats with reefers until crazy hours of the morning. We'd always have discussions about the effluent from our protein skimmers...Some reefers tune their skimmers to remove dark, nasty concentrated "skimmate"; others run it "wet" and almost clear. Both sides claim they're removing "undesirable stuff" from their tanks.  It's essentially an extract of organic and other materials...So we'd ask each other- would YOU add the "skimmate" to your tank?

And the answer from all sides was always a resounding "Hell no!"


So, that's my mindset in a nutshell.

It's less about an actual "detected risk" as it is about engaging in a practice that, to me, seems like your just adding some concentrated pollutants to your tank along with the desirable stuff. Trying to eliminate a possible cause of pollutants from going into my tanks is always a good idea, IMHO. Yeah, and I know the usual response is, "Well, you're wasting a lot of the tannins when you dump out the prep water into the garden..."

My response?

Try this: If you follow my advice and dispose of the prep water, and then place your botanicals into some fresh water for a little "post boil soak"- see just how quickly the water tints up like 90% of the time. IMHO, I don't think that you're wasting much tint-producing tannins at all by ditching the "tea." I just don't.

Yet, we still go back and forth on this. 

I suppose there is no real "right or wrong" answer to the topic, exasperating though this may seem. It's really a matter of personal comfort, preference, and...habit. One could argue both sides effectively...One of the better ones I heard was that when you boil stuff (and water boils at 212F/100C), you're wiping out most bacteria and possibly breaking down most why would this stuff be problematic at this point? Well, then it's a solution of concentrated dead bacteria and dirtwhcih you're adding to your tank at that point, right? 😜.

I still just "go with my gut" on this one. And, by the way- our succulents have never looked better, lol.


What's your take on this...?

Stay diligent. Stay curious. Stay consistent. Stay bold. Stay creative...

And Stay Wet.


Scott Fellman

Tannin Aquatics 

Scott Fellman
Scott Fellman


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