Hi, I am a beginner and I bought a 29 gal tank (12"x30"x18"). I have a marineland 50 gallon filter, (I think model 200) it moves 200 gal per hour. I was anxious to get some African cichlids so yesterday I went and got one tropheus Duboisi, (2cm maybe less than an inch), one electric blue johanni, (about 2 inches) and one that I think is a red zebra (a little longer than an inch). It could be a female johanni because I couldn't find differences between female johanni and red zebras. My question is if I already made a mistake with these three, and if the are compatible what else can I add? I want as many as possible because of the filter capabilities. Please help, thank you.