They are like twirling and stay upwards on thier tail fins all the readings are fine ph is 7.0 the ammonia is 0 the nitrite is 0 and the nitrate is 10 I have already lost one fish because of this now I have 2 more that is doing the same way. Does anyone know what is making these mollies do like this then die off.
) Is their water dechlorinated? Sounds to me like some sort of parasite but I honestly don't know if you can medicate a tank with fry. Have you tried salt - mollies like brackish water - maybe that would help. Try 1 teaspoon per gallon to start with - but make sure it's pure salt, either aquarium salt or kosher salt with no additives (ordinary salt is no good as there are too many additives in it). Sorry I can't be more helpful. 
