Overstocking tank

20 gals sounds too small for a mbuna tank. a 75 would be a better starting point

Wow...one of the more interesting questions in the hobby. Yes, on the one hand, you are correct in that overstocking mbunas can reduce aggression. On the other hand, these are fish which live in alkaline waters and are thus more prone to ammonia poisoning, so water changes at small intervals are absolutely essential to keeping them alive in overcrowded conditions.

That having been said, it is not recommended by any of the authors of the Malawi books in my possession, nor by those who have written recent magazine articles on the subject (as far as I know about recent articles, anyway...)

Also, your 20 is wayyy too small for any mbunas. I agree with the suggestion of a 75+, but I would carefully stock it with juveniles of unrelated species (as much as possible, in order to avoid hybridization), and not overstock it.

In my experience, overstocking isn't much benefit in tanks smaller than 75 gallons. The point of overstocking is to disperse aggression. As the aggressor fish chases a target, he gets distracted by another fish, goes after the second target, and then a third, etc. The idea is that no single fish gets constantly hounded and harrassed. Smaller tanks (i.e., <75 g.) just don't have enough swimming space for the aggressor to get distracted and he will continue to pursue his victim.

Overstocking puts you much closer to the edge, in terms of the margins of error. Management of the nitrogen cycle is terribly important, because these fish produce lots of waste and because the high pH makes any ammonia present much more toxic. Also, if there is a power outage, the risk of oxygen depletion in the water is much greater. Finally, you have to be prepared to do a LOT of water changes if you overstock, or you will have chronically high nitrates and other pollutants.

Finally, I strongly agree that a 20 is much too small for almost all Rift Lake cichlids, no matter how many. You might be able to house a couple shelldwellers in that size tank, but I'm not so familiar with those species.

HTH,
Jim

Wow, Jim pretty much mentioned it all...

I agree with him in thatit doesn't make fish less aggressive, it just occupies the one that is always chasing around the others... In saying this, I don't even think I'd put one Mbuna let alone overstocking a 20 with them...

I suggest you either go with some smaller shelldwellers, or some dwarf species (e.i. Rams) Or maybe some Kribensis.

Meeki Man, would Neets be a good suggestion for a tank that small? All the color of Tropheus, but a lot less of the size...I just don't know about aggression levels...

hehehe, you could store the girls at my house while your 'rents are around

Personally, I think a 20 is too small for a breeding colony of auratuses. Further, those guys are so common, I have a hard time imagining you could make enough profit from breeding them to buy fish food, much less a new tank.

Sorry...

Jim