Sun Dwarf Platty's
So, I just got four new sundwarf plattys. I've had them before and I loved them, but they died rather mysteriously. One seemed to deflat and the other seemed to puff up. This was within a week of each other. None of the other fish in my tank were affected and I assumed it was something natural they had gone through. So, I've bought four younger ones, 2 males and 2 females, though one of the males was playing with his fin so he could be a female. I know they'll eat the tropical flakes I fed them before, but they don't seem to be eating the frozen daphnia I've been feeding my baby bettas and the single guppy in that tank. Do they just not eat daphnia? It wouldn't be too much of a trouble, I would just have to specialize feeding in that tank.
So, anyway, yeah can anybody help me with that?