Water with "flavor", and the distinctions between color and clarity...

These "white waters" contain large amounts of dissolved and suspended solids, which are produced by weathering of the soils and rocks high in the Andes. This  rapid "weathering" produces the seasonal turbidity we're talking about here. Examples of "white water" rivers would be the main course of the Amazon, as well as the Japura and Jurua rivers.

By contrast, black waters flow primarily through the Guayana Shield, which has been weathered so extensively over the eons that it contributes only small amounts of suspended and dissolved solids into the water. We've talked about this many times before.

More confusing (or interesting, actually): Because it receives both whitewater and blackwater tributaries, the Orinoco is a mixture of water types with of strongly contrasting physical, chemical, and biological characteristics. A most interesting mix!

And then, there are rivers like the Tapajos or the Xingu, which have an almost greenish tint to them, although ecologists classify it as a "clearwater" river.  They flow from the geologic structure known as the "Central Brazilian Archaic shield", and have low amounts of sediments and dissolved solids. These waters feature a lot of wood and fine, sandy substrates. 

So, the point of all of this geological meandering to illustrate that the world of water is every bit as complex as any other aspect of the natural world.

And if it has you a bit confused, don't be. The point that I'm trying to make here is that the color of the waters which we obsess over are an amalgamation of a variety of factors, many of which we can replicate, to some extent, in the aquarium.

When we add materials such as leaves, wood, and seed pods to water, they impart tannins, humid substances, and other materials into the water.  This is similar to what happens in Nature, however, it's only part of the process, as we've discussed before.

And of course, you have the whole issue of turbidity and clarity.

we as fish geeks seem to associate color in water with overall "cleanliness", or clarity. The reality is, in many cases, that 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!

And it's kind of funny- if you talk to ecologists familiar with blackwater habitats, they are often considered some of the most "impoverished" waters around, at least from a mineral and nutrient standpoint.

In the aquarium, the general hobby at large doesn't think about "impoverished." We just see colored water and think..."dirty." 

And of course, this is where we need to separate two factors:

Cloudiness and "color" are generally separate issues for most hobbyists, but they both seem to cause concern. Cloudiness, in particular, 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.

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.

Okay, that was "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  natural, botanical-style blackwater 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?

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.

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."  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 among many hobbyists.

In my home aquariums, and in many of the really great natural-looking blackwater aquariums I see the water is dark, almost turbid or "soupy" as one of my fellow blackwater/botanical-style aquarium geeks refers to it. You might see the faintest hint of "stuff" in the water...perhaps a bit of fines from leaves breaking down, some dislodged biofilms, pieces of leaves, etc. Just like in nature. Chemically, it has undetectable nitrate and phosphate..."clean" by aquarium standards.

Sure, by municipal drinking water standards, color and clarity are important, and can indicate a number of potential issues...But we're not talking about drinking water here, are we?

"Turbidity." Sounds like something we want to avoid, right? Sounds dangerous...

On the other hand, "turbidity", as it's typically defined, leaves open the possibility that it's not a negative thing:

 "...the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air..."  

What am I getting at?

Well, think about a body of water like an igapo adjacent to the Rio Negro, as pictured above in the photo by Mike Tuccinardi. This water is of course, "tinted" because of the dissolved tannins and humic substances that are present due to decaying botanical materials.  And it's also a bit "turbid" because of the fine particulate matter from these materials, too.

I would argue that these conditions are not "unhealthy" to fishes, right?

Okay, we've beaten the living shit out of that, haven't we?

Yeah.

The substrates that we utilize influence both the aquarium's appearance and its chemistry. This is, of course, essentially what happens in Nature. In the flooded forests of South America and elsewhere terrestrial materials, such as botanicals, roots, branches, leaves, and soil play a role in shaping the aquatic ecosystem which arises following the seasonal inundation.

The mix of materials which comprise these unique habitats has definitely been an inspiration for me to create quite a few different aquariums over the years! There is so much we can learn from studying these systems that we can apply in our hobby work!

That's different from "cloudy" or "turbid", however. 

It's a distinction that neophytes to our world should make note of. The "rap" on blackwater aquariums for some time was that they look "dirty"- and this was largely based on our bias towards what we are familiar with. And, of course, in the wild, there might be some turbidity because of the runoff of soils from the surrounding forests, incompletely decomposed leaves, current, rain, etc. etc.

None of the possible causes of turbidity mentioned above in these natural watercourses represent a threat to the "quality", per se. Rather, they are the visual sign of an influx of dissolved materials that contribute to the "richness" of the environment. It's what's "normal" for this habitat. It's the arena in which we play in our blackwater, botanical-style aquariums, as well.

Obviously, in the closed environment that is an aquarium, "stuff" dissolving into the water may have significant impact on the overall quality. Even though it may be "normal" in a blackwater environment to have all of those dissolved leaves and botanicals, this could be problematic in the aquarium if nitrate, phosphate, and other DOC's contribute to a higher bioload, bacteria count, etc.

Again, though,  I think we need to contemplate the difference between water "quality" as expressed by the measure of compounds like nitrate and phosphate, and  visual clarity.

My hypothesis:

Our aesthetic "upbringing" in the hobby seems to push us towards crystal clear water, regardless of whether or not it's "tinted" or not. 

A definite "clear water bias!"

And think about it: You can have absolutely horrifically toxic levels of ammonia, dissolved heavy metals, etc. in water that is "invisible", and have perfectly beautiful parameters in water that is heavily tinted and even a bit turbid. That's why the aquarium "mythology" which suggested that blackwater tanks were somehow "dirtier" than "blue water" tanks used to drive me crazy.

It doesn't bother me anymore.

Color alone is not indicative of water quality for aquarium purposes, nor is "turbidity." Sure, by municipal drinking water standards, color and clarity are important, and can indicate a number of potential issues...But we're not talking about drinking water here, are we?

No, we aren't! 

Those of us in the community of blackwater, botanical-style aquarists seek out tint and "body" in our water...while the rest of the aquatic world- well, they just sort of... freak the fuck out about that, huh?

Our aesthetic "upbringing" in the hobby seems to push us towards "crystal clear water", regardless of whether or not it's "tinted" or not. And think about it: You can have absolutely horrifically toxic levels of ammonia, dissolved heavy metals, etc. in water that is "invisible", and have perfectly beautiful parameters in water that is heavily tinted and even a bit turbid.