heterandria formosa not breeding

ok i know these are meant to be the easiest fish to breed but its just not happening. in my 5 gallon tank i have 2 golden hets and 1 pair of normal hets. the normal het female is really skinny and when i feed her she has a bulge but soon loses it again. they are fed with these 'delica-sea' fish food flakes that contain really only meat and fish. the male is trying desperately hard to mate with them but there not getting pregnant. this is the third time that i have tried this fish can anyone tell me the problem?

They on their own now then.

Normaly they produce 1 or 2 fry every few days.

And they dont usualy eat their fry unless there not feed propley.
But things sound fine. You'll have to just keep trying.

If u can feed brine shrimp then there best, flake should be fine.

Alan

thanks i'll try that. one thing weird i have noticed about the male is that he can change colours to match with the type of female! when i bought it it was a olive green with a brown stripe but now i think he doesnt like being himself and turns into a golden colour similar to true gold males! maybe the normal coloured female is infertile or passed her time or sumat