New to cichlids and want to make sure i am doing things right. I have a 60 gallon tank, with 1 big yellow lab, 4 blue johannii, 2 acei, 1 electric blue, 1 catfish, and 2 pleco. Running a fluval 304 filter, and have about 4 caves and other hidding spots under and round the rocks. Do a 5 gallon water change every 2 weeks. Water and tank is always clean looking. Am i changing enough water? Also thinking about getting a couple more Mbuna fish or is this a bad idea. One big blue johannii chases other fish around, but he is the dominalnt male in the tank (2 males and 2 females, fish was given to me so i couldn't pick the sexes out).