Help with Aquamaxx AF-1


So I finally installed my AF-1 filter roller last night. Went to bed happy. This morning I go to check on it and discover it has rolled out the entire roll overnight. After watching it closely, what is happening is that it gets just a very little detritus in it and that is enough to raise the level of the water inside to trip the float valve and roll it forward. I have the unit mounted 1.5 inches below the water line from the top of the intake as suggested. My only thought as to why this would happen would be if I had too much flow going through it, but it says it's rated for 1350 gph. My return pump is a mag 18 with 6 feet of head which should be putting out only about 1050 gph. When it first starts out, the water inside the chamber is about an inch above the water in the sump and then as stated it takes almost no detritus to make the water level rise to the point it flips the float valve. When I look at the spent roll, it is literally all still white. Any ideas what is going on?