I have a 75 Gallon Freshwater cichlid tank. I have a Cascade 1000 canister(295gph) with the intake located on the right corner.. and the output located at the left corner.. I also have a power head (300gph) on the right side of the tank. It's located on the top of the water. It reaches about 75% across the tank.. however on the far left side of the tank there is a white film that always comes back even if I siphon it.. I have read that it's due to not enough water agitation.. however I can't find anywhere online as a fix for this. I also have been told not to put too much circulation or water agitation in the tank due to stress for the fish. What can I do to fix this? Thanks.