There's a lady with a home business that sold me some cichlids last winter. She kept a few of them in her show tank that I had ordered through her because she liked them and she had ordered extra. Well I haven't been there since but I went back yesterday and those same fish are twice the size of mine! I thought mine were doing good because they reproduce like crazy but wow something's wrong. The only difference I could see is that she has a 150 gallon and I have a 120 gallon. I have about 25 fish in mine (5 groups of 5) and she has about 15 (1 of every kind). I only do a once a week change so I don't know how often she cleans hers...also I know she keeps her ph high and mine's only at about 6.5-7. My water is really hard too so I'm not sure what cichlids like but I do keep my nitrates under 20. What's going on with my tank? Is it the low ph and lack of water changes? If I fix this now will they grow? Should I get rid of some?