Underwater influences...

II think we can't talk too much about how the physical structures of aquatic habitats influence well- EVERYTHING! I mean, water flows through all sorts of submerged physical structures, ranging from tree trunks to leaf litter assemblages- and that has a huge physiological-chemical influence on the habitat overall as well.

It's very easy to overlook this simple fact in our quest to create cool-looking tanks!

You could take your aquarium design vis-a-vis hardscape further and manipulate water flow patterns and such to allow botanical materials to accumulate in certain areas, or allow stands of certain types of plants to grow in specific locations within the aquarium. Understanding (or at least, observing) how physical barriers, like wood and rocks are oriented by water currents, local geology, and even weather, and also impact the movement of water in a given area, could help you create some interesting scapes.

Lately, it's been all the rage among competitive 'scapers to "break the waterline" with wood. And it's cool. I like it.  It has a neat look. Yet, I have to admit, albeit a bit sheepishly- that after seeing several hundred pics of tanks with driftwood heading out of the water (and having done some myself), I can't help but think it's become too much of a "formula":  "Assemble group of rare aquascaping rocks, insert manzanita branches in vertical orientation with respect to 'Golden Ratio' and break water line. Done."


Or I Might even say, "vomit"...'cause you know I won't hold back on how I feel about this stuff. How can we save this from becoming another "Scott-hates-the-'social-media- aquascaping-world'-and-sounds-like -an-asshole" rant?

What about approaching this from the standpoint of how and why this would happen in Nature?

I mean, ask yourself under what circumstances would a piece of wood break the waterline? If you study streams and other bodies of water, the reasons are relatively few, but fairly apparent. Likely, one of a few scenarios: 1) A big branch falls into shallow water, with part of it sticking up out of the water.  2) A fallen branch, limb, trunk, or entire tree is covered by water when seasonal inundation submerges the forest floor 3) A tree or shrub growing along an actively-flowing river or stream becomes partially submerged by a large seasonal influx of rain or tidal increase.

It's the same for rocks, and the distribution of substrate materials, botanicals, and leaves. If we ask ourselves how and why these materials accumulate the way they do in nature, the answers create many interesting and inspiring situations for aquascaping.  Making the study of natural structures in aquatic habitats part of our inspiration "lookbook" and incorporating them into our "tradecraft" has, IMHO, always yielded more interesting, long term functional aquariums.

In addition to these purely artistic interpretations, (which are beautiful for the most part-I'll give you that) even more amazing, more functionally aesthetic and realistic aquariums can be created by simply looking at what caused these habitats to form in nature, and assembling and placing the components you're using based upon that.

The idea of simulating fallen tree trunks and logs and branches  in aquariums is as old as the art of aquarium keeping itself. However, I think the approach of looking at them not just as "set pieces"- but as the foundational cornerstone of a biological and physical habitat gives new context to the practice. Rather than just, "Woah, that peice of wood is a great place for my cichlids to hide!", perhaps we could think about how the wood provides foraging or a corralling feature for leaf litter, soil, etc.


Everything from driftwood to twigs to roots has an important place in simulating the function and look fo the aquatic habitats we love so much. Simply looking at this stuff from a purely aesthetic standpoint sell it short, IMHO.

Combinations of these materials (contained in various ways) could create an interesting functional AND aesthetic terrestrial component that could influence the water chemistry and ecological diversity of our systems.

Asalways, the big opportunity here is not only to create a realistic, compelling display- it's to further unlock some of the secrets of nature and study the interactions between land and water.  It's about incorporating function into our displays, and appreciating the aesthetics which accompany it!

Stay inspired. Stay creative. Stay observant. Stay diligent. Stay open-minded...

And Stay Wet.


Scott Fellman

Tannin Aquatics 

Scott Fellman
Scott Fellman


4 Responses


March 27, 2019

Oh yes and one think I noticed and was disappointed with the two new pieces of wood (one light coloured one very dark) was that they did not leak tannins unlike the older wood in the tank (much eaten by the bristlenose ancistrus cat did when it was new (I of course did not mind in the least). Which is part of my suspicion about at least the lighter one which has darkened. It is a bit holey though and has a large surface area in total.

As a woodworker I can attest that wood will absorb liquids to a sometimes extraordinary degree. Which is why things like a sealing coat of thinned shellac (sanding sealer) is often used. I especially use it on exposed end grain to stop it going very dark with the finish so I certainly do not discount that a piece might absorb stain. The water from boiling them was VERY dark.

I had intended to only boil them for a minimum period to get them to sink but got distracted with other things such as tearing down the old tank and putting it back together all in one day with the fish in a bucket with the old wood and plants with air and heating and lots of other buckets with aged tank water.

Another thing is I have a thickish underlayer of humate in the tank under the pea gravel and was surprised that it DIDN’T tint the tank. The plants appreciate it though, I have GREAT plant growth with that a longer, brighter lamp.


March 27, 2019

Hi, thanks for your comments. The piece of wood in question is becoming noticeably darker as I have been trying to saturate the system with the blackwater from the alder cone boil up. I had to boil it to get it to sink as 2 days soaking had not achieved that. I stupidly tipped the water down the drain though, only realising my mistake afterwards.

I have also just cleaned the tank and filter and the ceramic beads have darkened as well. Mostly the larger older type with the hole down the middle, not so much the newer smaller sort without the hole.

So I have concluded that both are tannin sinks and have been trying to saturate them with regular topups of the blackwater and the degree of clearing in the tank is at least slowing down. It is now rather dark with another bolus thawed into the change water. So fingers crossed.

I had to do an intermediate water change with the nano tank as it was rather too dark. I also removed some of the catappa leave parts into the main tank.

Oh yes and I added a split up nano catappa leaf to the upper basket of the filter so it has water flowing over it constantly and its output will be unfiltered as it exits into the tank.

The acidity has dropped independently of the colour though. It’s about pH 5.5 at the moment. I have bicarb standing by to inhibit further reductions.

Meanwhile my attempts to provide the dwarf chain loaches (B. sidthimunki) with baby snails to eat was thwarted as they attacked the fully adult ramshorn snails I added. I’ve had much larger B. lohachata in the past who have ignored adult snails but waited by hatching egg patches picking off the babies as they emerge.

I’m growing more snails in the nano and daphnia tanks and will feed the loaches baby snails as they hatch or slightly larger. There are a LOT of egg masses in the nano tank. The hunger and enthusiasm for snails in the sidthimunkis makes me think providing them with live snails should perhaps be a necessary part of keeping them.

Now, how to encourage a healthy growth of hydra for my pearl gourami in which enough of them survive to make more . . .

Scott Fellman
Scott Fellman

March 19, 2019

A most frustrating thing for us tint lovers!

I’m not sure about wood absorbing tannins. I don’t think that it’s porosity or structure necessarily has anything to do with that…especially because you read Aquascaping forums where people are freaking out because their piece of dogwood keeps EMITTING tannins, lol!

Rather, I suspect it’s one of the chemical media you’re using. Now, while I’m not aware of the capability of ion exchange resins to remove tint, I suppose it’s possible. Perhaps there might even be carbon, or some other selected material that has an affinity for stuff like tannic acids, in the media; not sure. I suppose my first experiment would be to remove the chemical filter media and work backwards. Although I have always ran some chemical media in my blackwater tanks (and you can see the types of color I get), I have long suspected that it’s about who much you use in proportion to water volume. One media that I have used without removing “tint” has been Seachem “ReNew”- seems to selectively remove organics without taking out the color…Again, no perfect answer here; just more things to experiment with. Keep experimentinG!



March 18, 2019

I have a Fluval 106 external filter with foam, ceramic beads and of late phosgaurd phosphate and silicate absorbant beads but now JBL Phos Ex. I cannot keep the water of the tank dark for more than 2-3 days before it clears.

I suspect the filter but I suppose it might be one of the pieces of bogwood absorbing the tannins as well. There are more than enough catappa leaves and I made blackwater by boiling up alder cones. I put enough in to make the tank water teak coloured now it’s barely weak tea coloured.

It also has lots of white oak leaves, guava leaves and beach leaves, a good thick leaf litter. The oak leaves are doing very little as well.

A nano tank with just a foam filter and no bogwood is nicely dark and staying that way. Same leaf litter, equivalent amount of blackwater. It seems to have gotten darker as well. Yin and yang tanks.

Any ideas on how to keep the main tank dark?

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