It all depends on the cichlids being kept. Africa is a big place! West African species like jewels and kribs prefer soft, slightly acidic to neutral water (pH 6-7, 5-10 degrees dH). Lake Victorian cichlids on the other hand want water that is neutral to slightly basic and a little bit hard (pH 7, 10 degrees dH). Then again you have the cichlids of Lake Malawi which want hard, basic water (pH 7.5-8, 10+ degree dH). And then there are estuarine species like
Sarotherodon melanotheron that come from brackish water, so need some marine salt mix added to their water (SG 1.005 is ideal).
One common mistake is to think you can keep them all in the same tank. As should be clear, you can't. At least, not if you intend to do well. Kribs for example may live in hard water, but the sex ratio of their offspring will be completely off. For equal numbers of male and female fry, you need a pH of precisely 7.0. Conversely, if you keep Malawians in soft water, they'll never be healthy and will likely die prematurely.
On top of that you have differences in social behaviour. Mixing Tanganyikans and Malawians is unfortunately all too common, and with a very few exceptions, most species from each lake mix very poorly with species from the other. The notable exceptions here are
Tropheus spp, which come from Lake Tanganyika but are so aggressive they do rather better with mbuna of equivalent size than with Tanganyikans.
In any event, 25 US gallons is insanely small for most African cichlids. The exceptions would be a breeding pair of
Pelvicachromis (which need soft, slightly acidic to neutral water) or else a collection of shell dwellers from Lake Tanganyika (which must have very hard, basic water of excellent quality).
Cheers, Neale
Could someone please help me with a set of water parameters for African Cichlids? (sorry I can't be more specific about species, but I haven't picked them out yet. It will be a mixed species tank though)
