It should work fine as long as you change it as required. You say tumble, GFO shouldn't be tumbling too fast. If it churns to fast, it can grind down and cause dust particles to be expelled. At least that's what I was told. I only run about 3" in my Phosban 150 reactor and have the flow down so only really the very surface moves. I also look to make sure that the tiny particles aren't being lifted up and out. Hope this helps.