Hello; If the stuff is not some sort of creature, here is my thought. If a tank does not have some sort of device to mechanically disturb the surface of the water a protein film can form on the surface. When this film is disturbed it can break into whitish flakes.
A simple fix is to run an air bubbler. The out flow of a power HOB filter can also break up the film if the water level is not too high. If the water level is high the outflow does not always disturb the surface enough to break the film.
A simple fix is to run an air bubbler. The out flow of a power HOB filter can also break up the film if the water level is not too high. If the water level is high the outflow does not always disturb the surface enough to break the film.
