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"Let's be clear about this..."

Tannin Aquatics

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As fish geeks, there are a few things that we universally seem to agree upon, right?

I mean, everyone knows that Characins are the best fishes for aquariums. Or is that Dwarf cichlids? Or maybe Plecos. Or? 

Okay, well the ONE thing I KNOW we can all agree on is our love of crystal clear water in our aquariums. Let's face it: Nobody likes a cloudy aquarium! 

As fish geeks, we want to be able to enjoy our aquaecapes, admire our fishes, and relish our plants. However, for various reasons, clear water is sometimes evasive. The good news is that most of the common cloudy water situations have relatively easy remedies.

As more and more hobbyists embrace the use of aquatic botanicals in their aquaria, we're seeing more and more tanks with a golden brownish-colored "tint" to the water. Now, let's be clear (arghhh!) about one thing: There is a difference between "color" and "clarity."

The color is, as you know, a product of tannins leaching into the water from wood and botanicals, and typically is not "cloudy." It' actually one of the most natural-looking water conditions around, as water influenced by soils, woods, leaves, etc. is ubiquitous around the world. Other than having that undeniable color, there is little that differentiates this water from so-called "crystal clear" water to the naked eye.

Of course, the water may have a lower pH and general hardness, but these factors have no bearing on the visual clarity of the water.


I remember fondly (oaky, perhaps less than fondly), when I was co-owner of Unique Corals, I had a beautiful little blackwater aquarium in my office.


Everyone who came in my office aged into that aquarium; most were hardcore "reef people" and marine livestock vendors. And if I had a dollar for every time someone told me, "Man, you MUST be busy! That aquarium looks pretty dirty. You need to change the filter...!"  Yeah. Once I explained what blackwater is and how it was natural and, in my eyes desirable, they would either have an "Ahah!" moment, or just continue with the business at hand, shrugging off my explanation. 

The point is, we seem to associate color in water with overall "cleanliness", or clarity. The reality is, in many cases, the color and clarity of the water can be indicative of some sort of issue, but color seems to draw an immediate "There is something wrong!" from the uninitiated!


 Cloudiness and "color" are generally separate issues for most hobbyists. As we all know, cloudiness can usually be caused by a few factors:

1) Improperly cleaned substrate or decorative materials, such as driftwood, etc. (creating a "haze" of micro-sized dust particles, which float in the water column).

2) Bacterial blooms (typically caused by a heavy bioload in a system not capable of handling it. Ie; a new tank with a filter that is not fully established and a full compliment of livestock).

3) Algae blooms which can both cloud AND color the water (usually caused by excessive nutrients and too much light for a given system).

4) Poor husbandry, which results in heavy decomposition, and more bacterial blooms and biological waste affecting water clarity. This is, of course, a rather urgent matter to be attended to, as there are possible serious consequences to the life in your system.

And, curiously enough, the "remedy" for cloudy water in virtually every situation is similar: Water changes, use of chemical filtration media (activated carbon, etc.), reduced light (in the case of algal blooms), improved husbandry techniques (i.e.; better feeding practices and more frequent maintenance), and, perhaps most important- the passage of time.


There are of course, other factors that affect clarity, like fishes that dig or otherwise disturb the substrate and wood with their grazing activities, but these are not necessarily indicative of husbandry issues.


"Aquarium Keeping 101", actually.

Although we all seem to know this, I hear enough comments and questions about the color of the water and its relation to "cleanliness" in "New Botanical" systems that it warranted this seemingly remedial review!

Remember, just because the water in a botanical-influenced aquarium system is brownish, it doesn't mean that it's of low quality, or "dirty", as we're inclined to say. It simply means that tannins, humic acids, and other substances are leaching into the water, creating a characteristic color that some of us geeks find rather attractive. If you're still concerned, monitor the water quality...perform a nitrate test; look at the health of your animals. What's happening in there?

I can think of at least one or two other things that are influenced by the same processes, which we accept without question in our everyday lives...


People ask me a lot if botanicals can create "cloudy water" in their aquariums, and I have to give the responsible answer- yes. Of course they can! If you place a large quantity of just about anything that can decompose in water, the potential for cloudy water caused by a bloom of bacteria exists. The reality is, if you don't add 3 pounds of botanicals to your 20 gallon tank, you're not likely to see such a bloom. It's about logic, common sense, and going slowly.


Remember, too, that some "turbidity" in the water, in either a "whitewater" or "blackwater" system, is natural, expected, and not indicative of a problem. In many natural settings, water is chemically perfect but not entirely crystal clear. Much like the substrate issue that we tackled yesterday, I believe that a lot of what we perceive to be "normal" in aquarium keeping is based upon artificial "standards" that we've imposed on ourselves over a century of modern aquarium keeping. Everyone expects water to be as clear and colorless as air, so any deviation from this "norm" is cause for concern.


I think that, with a greater understanding of the types of environments our animals come from, that this "clinical sterility standard" for water and overall aesthetics of our systems will change. The movement towards biotopes and more naturally-appearing systems has opened the eyes of many aquarists to the amazing possibilities that exist when we move beyond our previously-imposed limitations. The future may not be "crystal clear", but I believe that it is bright and full of potential!

Stay open-minded. Stay adventurous. Stay skeptical. Stay curious. And most important,

Stay Wet.

Scott Fellman

Tannin Aquatics



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