Clouds on the horizon...or in your tank?

In the aquarium hobby, we have an obsession with crystal clear water... Now, I'm not talking about water devoid of color...We have sort of reached a point where "tinted" water is accepted and even desired- a huge mental shift that many have made.

However, when it comes to clarity- that's still a "frontier" for a lot of hobbyists; perhaps even a "bridge too far" for some. That's a different "mental shift!" I wanted to return to this "clarity" idea again today, because there are some aspects of "clarity" that I think are sort of unique to the botanical-style aquarium. 

Of course, since botanical-style aquariums are conceived to operate differently in the first place, you've likely noticed that they aquariums display a number of characteristics which make them different from more "conventional" aquariums in function and appearance.

One of the things you might notice right from the start is that botanical-laden aquariums seem to have an initial "haze" or turbidity that is slow to clear. Now, part of this is no doubt due to the breakdown of the leaves, pods, etc. that we use: Surface dirt, lignin, and other compounds, bound up in the tissues of the botanicals, released into the water upon the initial submergence and after preparation of these materials.

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?

People ask me a lot if botanicals 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.

For that matter, plain old dirt and dust bound up in and on the surface tissues of many botanicals will be released, despite our best efforts at preparing them for use. Some stuff simply leaches into the water.

And the fact that many of us tend to not to use a lot of chemical filtration media in our tanks might have some impact on that, too. 

 It's also become a sort of "thing" now to use the formerly unthinkable "sedimented" substrate materials, which will, by their very composition, impart some cloudiness into the water for a few days or more after they're submerged. Because you don't rinse them like you would more traditional substrates, the cloudiness which inevitably occur is simply part of the process.

This is typically a temporary cloudiness, and will subside over time. It's not something that will forever haunt your aquarium, trust me.

And it's kind of cool, really, because it sort of replicates what occurs in natural aquatic systems upon the initial submersion of a formerly terrestrial habitat. This cloudiness is representative of a fundamental shift in how we operate our aquariums!

Another reason for this haziness is biological. 

Often, you'll experience a burst of microorganism/bacterial growth, which impacts the visual clarity as populations multiply rapidly in the "fertile" environment of a botanical system, with its wealth of organic materials supplied by the decomposing matter upon which these life forms feed.

And then there is what we call "infusoria."

One only need reflect on the classic "infusoria" cultures which every fish breeder can recall from his/her experiences- they're really cloudy! Remember, infusoria is a collective term for aquatic organisms like euglenoids, unicellular algae, ciliates, protozoa, etc.

In modern formal biological classification, the term "infusoria" is considered an antiquated, obsolete descriptor, as most of the organisms previously included in the collective term "Infusoria" are assigned to a different assemblage of taxonomic groups.

Nonetheless, it's a charming, albeit somewhat antiquated term that is still used in aquarium circles to describe the tiny organisms that arise when you soak some blanched lettuce, vegetable skin, or other plant matter in a jar of water. Or, when dried botanical materials are submerged in water!

Depending upon the density of the amount of materials and the population of the organisms in play, you could expect to see considerable cloudiness...

Now, I have placed a few drops of tank water under a microscope early in the life of several botanical-style tanks over the years, and I did see some microorganisms swimming around in there.

Of course, I am not a microbiologist, and for me to make any conclusive statements about "density" or "diversity" of the life forms I saw swimming around in my samples is a bit too amateurish! That being said, in most of these samples, I saw a fair amount of "some sort" of life forms swimming around in the water! 

Generally, I've found that the sort of "cloudiness" will typically clear after a week or two, as the "tug of war" between bacteria and "infusoria" achieves a sort of "equilibrium."

And, as mentioned above, the cloudiness could also be caused, at least in part- by the dissolving of the botanicals themselves. When you think about it, most plant parts, such as seed pods and such, are comprised of materials such as lignin, cellulose, etc., and their constituent sugars, starches, etc. And, because of this composition, will release these materials into the water column. This can happen over time, too..sort of becoming a "new normal" for your botanical-style aquarium.

Of course the idea of "cloudiness", in general, may be a "tip off" to some other issues in the aquarium. And, 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.

I like the "passage of time" part best.

Now, with the "cloudiness" caused by our "technique" or application of botanicals is a slightly different story. These are sort of "natural consequences" of what we do..

Now, you could intervene in this if you wanted to...Performing larger water exchanges, employing chemical/very fine mechanical filtration media, etc. Personally, I have learned over the years NOT to let this stuff phase me. I suppose I'm so deep in my own "mindset" about letting Nature do its thing, that I don't do much to combat it...

Once this initial "microbial haze phase" passes, there are other aspects to the water clarity which will continue to emerge. And I think that these aspects are similar to what we observe in Nature.

For example, I've noticed that in many of my aquariums, particularly those with certain types of wood (like mangrove, Melastoma root, "Borneo Root", etc.), you'll get more of this "patina" to the water. Again, I'm in the realm of speculation here, but I can't help but wonder if certain wood and botanical materials/leaves have a greater content of organic materials (or more readily release these materials into the water because of their structure), lignin, tannins, etc.

One of my friends calls this "flavor", and his moniker makes sense, when you think about it!

And I think that this is a really interesting phenomenon, which is distinctive to our botanical-stye blackwater/brackish aquariums. To accept it is a choice, and it definitely requires the adoption of a mental shift to appreciate that this is very similar to what we see in many of the natural aquatic systems that we attempt to replicate.

In Nature, the accumulations of decomposing plant materials, leaves, soils, and sediments all contribute to this cloudiness or turbidity of the water. In our aquariums, it's pretty much the same.

Yes, I understand that an aquarium is NOT an open, natural system, and that there are fundamental differences between the two.

However, to see some of the processes, aesthetics, and what we call "functional analogies" (i.e.; the way materials break down, re-distribute within the tank, and how the aesthetics and water chemistry are affected by water exchanges, etc.) take place in our aquariums, we can't help but think that we're "on to something" here.

What happens in the wild often happens in the aquarium- if we let it play out.

(Image by Aquariumaniak Khizanishvili- a master of the "dirty" aquarium!)

So, yeah, our aquariums may NOT have the "crystal-clear", colorless water which many hobbyists envision when they think of what an aquarium "should" look like. Yet, with the continued, evolving work which our community is doing, we'll continue to discuss/analyze/debate the merits of such clarity profiles in our systems.

Nature- our muse and inspiration for everything we do- provides unlimited examples of elegant, healthy, well-balanced aquatic habitats which look quite contrary to what have come to expect as hobbyists over the years.

As we've discussed a lot lately, we're absolutely obsessed with the natural processes and aesthetics of decomposing materials in our aquariums. And of course, this comes with the requirement of us to accept some unique characteristics, of course!

We have taken our first tentative footsteps beyond what has long been accepted and understood in the hobby, and are starting to ask new question, make new observations, and yeah- even a few discoveries- which will evolve the aquarium hobby in the future.

So, there may be "clouds" in your tank, but defintely NOT on the hobby's "horizon!"

Stay curious. Stay observant. Stay engaged. Stay bold...

And Stay Wet.


Scott Fellman

Tannin Aquatics 



Scott Fellman
Scott Fellman


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