[Peter Finke]

Nico, very young fish will sometimes not respond positively to being transferred to another tank. If they are two months old, it’s no problem any longer. Perhaps it would bei a better idea to transfer the old. Very often, they react with immediate new breeding. Or put the young in a two liter round glass using the old water and feed carefully not too much. You can stir around the water once a day, the debris will assemble in the middle of the bottom and coukld be siphoned easily. Then give a small amount of new water. This is a well developed method!