I am also having the same problem as elettrone with the top filter intake! Bottom is working, I can see in the filter there is flow coming up but the top surface intake is doing nothing, which is causing what looks like a biofilm build up on surface. I have had this tank a 2/3 years, it’s been working perfectly fine up till now. I’ve just changed the filter media “old for new” if I remove all filter media flow restores to normal, but I don’t understand why the filter media would cause this as they are the same brand and media for the filter. The only other thing I can think of it being due to is that some how the motor has weakened in some way. (FYI I’ve the same tank as Elettrone the only difference being mine black not white) I have checked the rubber ring seals and all looks normal, the only thing I can think of it being is a motor malfunction/burnout making it not run to optimal performance. Any advice would be appreciated!
