maddog10 wrote:In a small tank like a 20g, I would suggest Mbuna from Lake Malawi. Probably a colony of Cynotilapia afras. If you keep up on the water changes, you could keep 10-12 fish. (Keep up on the water changes)
I'm afraid to disagree there. In my view a 20g is one of the worst tanks you can put mbuna in (10g is worse again) as an ABSOLUTE minimum no tank smaller than 36"by12"(by whatever hight, preferably 18"to24"), with 4foot being the realistical size tank for long term care, should be used to house mbuna.
for a 20g i would go for shelldwellers (for hardwater) or kribs and similar pelvichromis sp (for softwater) remember there isnt a lot of space in such a tank so your choises are limited. personally i would go with shelldwellers as you can keep a fair number of them and therefore see some intresting social behaviour.
however a pair (or trio, not sure how well behaved kribs are) of kribs with dithers should be an interesting tank.