I am fairly new to the fish world. I have a 55 gallon fresh watter tank that has been set up for about 2 months now. There are 3 Bala sharks, 2 Jack Dempsey's, 2 Raphael cat fish, 1 pleco, 1 Jeweled Cichlid, 3 Pink Convicts. There are artificial plants set up in the tank. 2 of the Bala's have...