My cherry red females keep egging up yet only hold the eggs for a couple of days externally before they all vanish. Subsiquently I have no off spring yet. Is it anything I'm doing? The tank has zero fish in it so theoretically zero predation. The adults appear happy and I believe I has both male and females as 3 of them are a lot lighter in colour then the females that do produce eggs. I'm sure I read that they don't need any special requirements to succesfully breed and for juveniles to come through or am I wrong?