One of the topics we receive a lot of questions about concerning blackwater, botanical-style aquariums is what sort of ongoing maintenance procedures are necessary, and what sort of challenges you face longer term with these tanks...We could probably write many blog posts about this interesting topic, but an initial "quick hit" today will hopefully jump-start the discussion! (oh, and maybe answer some questions along the way!)
First off, one of the things that we all experience with these types of systems is an initial burst of tannins, which likely will provide a significant amount of visible tint to the water. If you're not using activated carbon or some other filtration media, tis tint will be more pronounced and likely last longer than if you're actively removing it with these materials! You might also experience a bit of initial cloudiness...this could either be physical dust or other materials released from the tissues botanicals, or even a burst of bacteria/microorganisms. Not really sure, but it usually passes quickly with minimal, if any intervention on your part. Oh, and not everyone experiences this...often this is a phenomenon which seems to happen in brand new tanks...so it might not even be directly attributable to the presence of the botanicals (well, at least not 100%). Could be the sand, or other dust/dirt from the other hardscape materials or the tank itself.
So, that being said...what happens next?
Well, typically, as most of you who've played with this stuff know, the botanicals will begin to soften and break down over a period of several weeks. As we've discussed ad nauseum, you have the option to leave 'em in as they break down, or remove them (whatever your aesthetic sensibilities tell you to do!). Many "Tinters" have been leaving their botanicals in until completely decomposed, utilizing them as almost some sort of botanical "mulch", particularly in planted aquariums, and have reported excellent results.
Sure, the stuff will go through that biofilm phase before ultimately breaking down, and you'll have many opportunities to remove it...or in the case of most hobbyists these days- add new materials as the old ones break down...completely analogous to natural "leaf drop!"
I have never had any negative side effects that we could attribute to leaving botanicals to completely break down in an otherwise healthy aquarium. Many, many users (present company included) see no detectable increases in nitrate or phosphate as a result of this process. Of course, this has prompted me to postulate that perhaps they form a sort of natural biological filtration media and actually foster some dentritifcation, etc. I have no scientific evidence to back up this theory, of course (like most of my theories, lol), but I think there might be a grain of truth here!
Oh, speaking of "grains"- one of the "bummers" of botanical aquarium keeping is that you will likely have to clean/replace prefilters, micron socks, and filter pads more frequently. Just like in nature, as the botanicals (leaves, in particular) begin to break down, you'll see some of the material suspended in the water column from time to time, and the bits and pieces which get pulled into your filter will definitely slow down the flow over time. The best solution, IMHO, is to simply change prefilters frequently and clean pumps/powerheads regularly as part of your weekly maintenance regimen.
And of course...this is the elegant segue into the part about your "weekly maintenance regimen", right?
Well, here's my thought on this: Do "whatever floats your boat", as they say. If you're a bi-weekly-type of tank maintenance person, do that. If you're a once-a-month kind of person...Well, you might want to re-examine that! LOL. Botanical-style blackwater tanks, although remarkably stable once up and running, really aren't true "set-and-forget" systems, IMHO. You want to at least take a weekly or bi-weekly assessment on their performance and overall condition. Now, far be it from me to tell YOU- the experienced aquarist-how to run your tanks. However, I'm just sort of giving you a broad-based recommendation based upon my experiences and those of many others over the years with these types of systems. You need to decide what works best for you and your animals, of course...
Now, remember, you're dealing with a tank filled with decomposing botanical materials. Good overall husbandry is necessary to keep your tank stable and healthy- and that includes the dreaded (by many, that is) regular water exchanges. As we pointed out, at the very least, you'll likely be cleaning and/or replacing pre filter media as part of your routine, and that's typically a weekly-to bi-weekly thing. Just sort of goes with the territory here.
During water exchanges, I typically will siphon out any debris which have loved where I don't want 'em (like on the leaves of that nice Amazon Sword Plant right up front!), but for the most part, I'm merely siphoning water from down low in the water column. I'm a sort of "leave 'em alone as they decompose" kind of guy. And I'm not going to go into all the nuances of water preparation, etc. You have your ways and they work for you. If you want to hear my way some time, just PM me on Facebook or whatever and we can discuss. It's not really rocket science or anything, but everyone has their own techniques.
And of course, regular water testing is important. Not just for the information you'll gain about your aquarium and it's trends. It's important because we as proponents of the "New Botanical" movement need to log and share information about our systems, so we can develop a model for baseline performance of these systems, and perhaps sort of develop "standards" for techniques, practices, and expectations about these tanks. With so many people worldwide starting to play seriously with blackwater, botanical-style tanks, we're seeing more and more common trends, issues, and ways to manage them...a necessary evolution, and one which we can all contribute to! Share!
So, your testing regimen should include things like pH, TDS, alkalinity, and if you're so inclined, nitrate and phosphate. Logging this information over time will give us all some good data upon which to develop our expectations and best practices for water quality management.
Last, but absolutely not least- one of the most important parts of your "new life with botanicals" is observing and enjoying your tank! Understanding what's going on- expecting the biofilms, decomposition, etc. is only part of the process- that "mental shift" we talk about so much. The rest is observation of your animals and their reactions, behaviors, and overall health. How are they eating, coloring up, behaving? Have you noticed in changes- positive OR negative- since starting your blackwater adventure? Are they spawning? Have they stopped spawning? Have they started dying? I mean, it's that basic. And THAT important.
In the end, living with your botanical-style backwater aquarium isn't just about a new aesthetic approach. It's about understanding and processing what's happening in the little aquatic ecosystem you've created. It's about asking questions, modifying technique, and playing hunches- all skills that we as hobbyists have practiced for generations. When you distill it all- we're still just keeping an aquarium...but one that I feel is a far more natural, dynamic, and potentially game-changing style for the hobby. One that we need no longer be afraid of.
And you're right in the thick of things.
Stay bold. Stay enthusiastic. Stay curious. Stay methodical. Stay open-minded. Stay engaged...
And Stay Wet.