Dirt tanks and apistogramma questions.

[Rowdy Hotel]

I have a couple of low tech dirt planted tanks. One tank has fine gravel and another has coarser gravel as a cap over one and a half inches of dirt. I never siphon the gravel in these tanks when I'm doing a water change (which I've been doing more frequently since I added apistos). Nitrates are undetectable or barely registering on the quick dip strips. I've been wondering if the detritus building up in the gravel bed was bad for my apistos or rams in any way. I've actually been considering siphoning the tank a little to remove some detritus so the cap doesn't get clogged and seal off the dirt layer underneath from oxygenated water.

I was also in the process of mineralizing some more dirt to set up another tank and I was thinking of adding a thinner layer of sand as a cap. This would allow the detritus produced to sit on top of the sand and allow me to remove it during the next water change.

 

[dw1305]

Hi all,
The coarser gravel is bad for them, as they can't sift it like they would sand (they are Geophagine cichlids). Sand is better, but it will eventually end up underneath the dirt, as it is denser.

I'd try to get off as much gravel as possible and then add some sand, although I appreciate this is likely to make a horrible mess.

cheers Darrel

 

[slimbolen99]

Tried the exact same thing with larger grained sand. I will have to go downstairs and get a picture of the result. 75 gallons of mud is what I ended up with after a trio of apistos decided to dig a spawning cave under a piece of driftwood. NO FUN. I won't do it with dirt again. Now I know why folks only have a few tetras in their dirt tanks!

 

[guits]

I have a ten gallon breeding tank and 2 five gallon grow-out tank with about 0.75" of sifted potting soil and about 0.5" black sand above it. I started out with planted tanks before keeping apistogramma, so I am biased for maintaining planted tanks. I have had the ten gallon for 3 years now set up this way, and the mixing between the layers as far as I can tell is minimal, with the sand staying above the soil. As with all planted tanks with soil, you do find that if you try uprooting the plants or changing the layout, you can create a cloudy mess, but if you have prior experience with soil tanks, you probably already have experience with how to limit this (either being extremely careful with planting changes, or just not changing the layout once you have it designed). I have been very satisfied with the results. I have had bitaeniata and eremnopyge breed and raise young in the ten gallon tank without any trouble. You may get into trouble with other apistogramma that love to dig a lot (for example, I don't think the soil and sand combo would work with my kelleri, as the male is constantly digging and shifting the sand around). If your priority is to keep apistogramma and having a planted tank is secondary, then I would say avoid the soil. If you are like me and want a planted tank, then you can try soil with a sand layer above and make it work with the right fish.

I have a comment about using dark sand. I use black sand because aesthetically it matches the soil and I like the look. However, apistogramma references demonstrate that in the wild, they frequently live in environments with a light colored substrate. My fish in these tanks show a darker coloration. This color difference is not permanent in my experience. For example, I just moved some eremnopyge young to a tank with light colored sand, and within the same day they appear lighter than their siblings still in the tank with black sand.

 

[Mike Wise]

Yes, the substrate is typically light colored fine sand, but much of it is covered by a layer of darker leaf litter. In this respect, the bottom is dark.

 

[Microlepomis]

I wouldn't siphon it off unless it's severe. I breed all of my fish in dirt based planted tanks. I don't keep any real serious diggers--but I do keep HRPs, C. myrnae and a few other Cryptoheros in a dirted breeding tank and they don't dig enough to make an issue. You've got to be brave enough to include more sand than you've been told is allowable. Of course... you used to be told that soil wasn't allowable... so we see how that can go. I use 2-3" and I have lots of MTS constantly "venting" the substrate. I've had some of these setups maintained for years with no problems. And I agree with the others--I use sand, not gravel. I've got two pairs of fish spawning in dirt tanks right now--A. cac. and Honduran red points. And my plants look spectacular... The detritus is a vital part of the ecosystem. Of course you'll never successfully replicate a full ecosystem in your tank, but a biofilm/detritivorous bacteria are great components. I'm not out to produce industrial numbers of fry... but my fish parent raise I don't mess with brine shrimp. My parents simply herd the young around and stir up the detritus until the fry are large enough to eat some of Alan Repashy's Spawn and Grow gel food. There's no noticeable difference between now and when I used to feed brine shrimp nauplii. I let leaves fall, die and rot and I even let oak leaves that I add rot. If it adds up to the point that it's covering the bottom completely I may siphon some off, but typically between MTS, amano shrimp and ottos that never happens.

 

[gerald]

I tend to leave a lot of detritus in my tanks too - fry love to hide and feed in it. Most of my tanks have been running 12-20 years, and a few nearly 30 years. I use local clayey soil under sand/gravel for plants only in containers. That way I can remove the containers from the tank when I need to split up the plants. This is especially useful for Cryptocoryne, Vallisneria, Echinodorus and other strong-rooted plants that would be impossible to thin out without pulling up lots of soil if I let them loose to spread throughout the tank. I think the age-old fear of "dirty gravel" causing H2S poisoning and other problems might be true in tanks with coarse gravel and not enough rooted plants to balance the fish load. Using sand or a sand/gravel mix (so that not too much poop and food can accumulate under the gravel), plenty of rooted plants, and a not-too-heavy fish load, the roots will keep the substrate from becoming anoxic. If your fish load is on the heavy side, or you feed heavily, then siphoning detritus off the sand surface is probably a good idea. But as long as there's a dense live root mat under the sand you shouldn't ever need to push a gravel-vacuum below the sand surface, IMO.

 

[dw1305]

Hi all,

Of course you'll never successfully replicate a full ecosystem in your tank, but a biofilm/detritivorous bacteria are great components.

I think you are right, a lot of us follow this sort of approach. Have a look at this thread: <http://www.apistogramma.com/forum/i...ogramma-sp-breitbinden.9042/page-2#post-52724>, Ruki's A. breitbinden tank is my all time favourite, and this article <http://www.seriouslyfish.com/all-the-leaves-are-brown/>.

I think the age-old fear of "dirty gravel" causing H2S poisoning and other problems might be true in tanks with coarse gravel and not enough rooted plants to balance the fish load. Using sand or a sand/gravel mix (so that not too much poop and food can accumulate under the gravel), plenty of rooted plants, and a not-too-heavy fish load, the roots will keep the substrate from becoming anoxic. If your fish load is on the heavy side, or you feed heavily, then siphoning detritus off the sand surface is probably a good idea. But as long as there's a dense live root mat under the sand you shouldn't ever need to push a gravel-vacuum below the sand surface, IMO.

I do the same as Gerald, no syphoning in the substrate. I've gone over to pool filter sand, because if you mix sand and gravel the sand always ends up a the bottom. If you have a lot of rooted plants you don't tend to get a huge amount of mulm build up.

cheers Darrel

 

[Rowdy Hotel]

This is good to hear, I think I'll be a little more lax when it comes to removing detritus from the tanks now. Anyone have any idea if the sand allows for there to be pockets of anaerobic bacteria that will remove nitrates? I've set up another dirted tank with thick sand layer that will probably be housing some fecund livebearers and lots of plants.

 

[gerald]

Yes sand (and dirty gravel too) probably does support anaerobic de-nitrifying bacteria, but if your tank is full of growing plants then bacterial denitrification may be irrelevant. I'd be curious to know, if anyone does, how much nitrate removal can be accomplished by bacterial denitrification versus a dense rooted plant bed (Crypts, Val, chain-sword) on an equivalent area of sand bed in a typical fish aquarium. My gut feeling predicts the plants would win by a long shot, but there might not be any practical way to distinguish these two processes in a tank with plants, since there's probably de-nitrifying bacteria growing in the sand around their roots. I need to check Diana W's book again and see if she addresses this.