My baby on this way, how is it in the end ...
Hypoxia. There is a tank of oxygen used to install the device you buy the same oxygen on the solution. Or the water on the four or five days can also be
Water or hot weather, hot air pressure, and floating head breathing exogenous floating head is water hypoxia. Under normal circumstances, dissolved oxygen in the water below 1 mg per liter of fish will float, less than 0.5 mg per liter will suffocate death, high oxygen fish to 0.5 mg will die. Water hypoxia, to add air pump or filter. May be hungry or too high to get sick.
There may be too many fish inside, or the fish tank is too small