Hello. I have a small, heavily planted 6 gallon tank which I have been using to keep some endlers while deciding whether to divide them into my separate sex guppy tanks. I realise they are slightly over stocked, with two males and six females. In just over 3 months none have developed round gravid bellies and no fry have appeared. They were between one and two months old when they were placed in the tank. Is it just that they are still young? Or is it a water quality issue?