yeah i kinda wanna swap all the tetras out and maybe get a big group of bleeding hearts and a group of redtail hemiodus but they are hard to come by....anyways my tank is 4ft deep and tall tank, i wish i got the 6 footer though, but at the time when i purchase this tank it is housing my RTG arowana....I used to have a collection of africans and south american cichilds and this is the first time I got the nicaragua cichlids so i don't have experience with them, but i did my research and i've read that they are docile and non agressive compare to other north american cichlids, they reach up to 9". I got one male fore sure the other 2 i can't sex them yet, but i'm sure they are females. So far so got this cichlids hasn't cause any trouble and i haven't seen them nip or chase smaller fish.....