Iím still having issues with surface scum on my large plant tank. Hereís the thing, my 29 gal, non-CO2, low light plant tank has very little surface agitation, AND no surface scum. My 75 gal tank has medium light, pressurized CO2 injected, surface agitation from a powerhead pointed at the surface AND has major surface scum.
The only other major differences between the two tanks is the 29 gal is covered while the 75 gal is open top. Could be the reason for the surface scum? The two tanks also have difference substrate. The surface scum tank has eco-complete and the 29 gal. has inert sand.
The difference has to be either the open top or the substrate. Thoughts?
Plants are doing well in both tanks and I feed fish once a day.