Natural Detritus Management

[Pinkey]

Hello,

I have a heavily planted 135g cichlid tank. I respect conventional wisdom regarding water changes and removing decaying plant matter HOWEVER, my ultimate goal, whether reachable or not, is to have a perfectly balanced natural aquarium requiring only the addition of new water.

I have many little snails to help with plant matter and have recently introduced a colony of blackworms (too early to see if they take hold and thrive). What else is safe for the aquarium and will help encourage natural decomposition?

The oscars do tend to garden for me and I do collect all the floating waste a couple times a week. Fortunately the plants are hardy enough that they grow back at about the same pace as the gardeners harvest it.




The tank is connected to 25' of house gutter filled with aquaponic clay pellets and terrestrial plants. It acts as a wet/dry filter as well as natural filtering for a lot more. I also have a sump with blue filter pads under the tank for mechanical filtration.

P.S. I don't know why the second picture is still there as an attachment. I tried rotating it and saving it right side up and it still is sideways. I apologize for the oddness.

Thanks,
Nate

 

[FreshyFresh]

Super cool setup Nate!

Being an oscar keeper myself, I would think it would take some SERIOUS doing to keep nitrates <20ppm on a 6ft tank containing 2 full-grown oscars, which are nitrate producing machines. Frequenting another O keeper site, most there do a fin-level weekly water change for a 2 oscar tank to keep nitrates in check. Just adding top-up water would eventually skew your GH, KH and swing your pH as well.

 

[Pinkey]

Thanks. It is taking some serious engineering to get the nitrates consistently down. After a change they jump right to 30ppm in a few days and hover there.

My town has very hard water and the tank is so seriously buffered that the pH sits at 6.8 no matter what. All other readings are so close to 0 that the only number I pay much attention to is the nitrates.

I will not ever forgo the water changes unless I can genuinely do without them. It is a goal driven by poetic balance rather than wishing to avoid maintenance. Ultimately, I would also love to have 2 25-year-old oscars with no hint of hole in the head.

 

[fishorama]

Wow, that is 1 of the best big cichlid tanks I've ever seen! How about engineering an auto-water changer or pump assisted manual WC? Keeping nitrates under 40 in a big Oscar tank is pretty good in my book. The other thing could help is feeding less...5 days/week? Hard to resist the cichlid begging, they're so "personable" & insistant, lol.

 

[Pinkey]

I have thought about the auto changer. It is not near enough to any plumbing for me to do it myself. Our water also contains chloramine which must be treated as the water is introduced. It doesn't go away on its own like some of the other treatments municipal plants use.

I have tried reduced feeding for a few weeks at a time. Rather than skipping days (which I have tried but don't like much) I have used measuring spoons to measure exactly how much food I introduce to the ecosystem. If I underfeed much the fish seem to get irritable and it seems, to me, to miss the point if the fish aren't happy.

My current plan is to increase biomass of the plants so they continue to suck everything usable out of the water. We'll see what happens.

 

[FreshyFresh]

Pinkey, I'm not saying it won't work, but it is a completely different approach than I've ever read of before as it applies to an oscar tank. To me, with that thickness of substrate, combined with fish as messy as oscars you are always going to be battling nitrates. 30ppm nitrates isn't horrible, but it's not good right after a water change and as you know, can lead to hole in the head and tons of other issues with oscars. I'm assuming the nitrate level climbs by the day.

135g is a good sized tank, but for 2 full-grown O's, it's not. I think your plan would work excellent with a super light bio load. With 2 O's? I dunno.

 

[Pinkey]

I may always battle the nitrates but I will never give up trying to approximate nature's way of dealing with them. Certainly in a small pool without water flow it would be an issue in nature, too.

From what I can tell, the nitrates jump to 30 within 3 days of a change and don't get above 40 even in 2 weeks. Since 2012 I have not gone longer than two weeks without a water change. This is odd because everything I read suggests that nitrates are the final byproduct of the nitrogen cycle and not much digests them in an enclosed system.*

The first year I had the O's all the parameters were always out of control because the fish were growing so much faster than the bacteria.

*30 minutes later: It turns out there are bacteria that will digest the nitrates! All I have to do is build a coil denitrator! The concept is simple. It creates an anaerobic environment in which other bacteria can thrive! It can be gravity fed and should cost less than $30! http://saltaquarium.about.com/od/diydenitratorplans/ss/sbscoildenitrat.htm (the principles are the same for marine and freshwater)

This is exciting. This is another reason I love this forum; one comment can spark a whole new train of thought and a whole new way to solve some problem or other.

I still don't know why the nitrates never get that good or that bad, though. I am happy they sit in the middle but I don't know why. More plants and a denitrator! Onward!