hi sorry for my bad english i am a french canadian so i try my best to get understand my tank is a 65 gal 48 x18 x24 everything is ok now but even using with my sump return and a powerhead to get water agitation there is a small dust film floating in my tank how can i remive this thanks for your help i have think to get a gyre xf 250 to get more water agitation through the top of my tank instead of my two rossmont mover m1200 but i read its noisy