every now and then i'll use my vortex diatom filter, but it's very rare that i have to pull it out. as stated before me, using polyester in your filter defenately makes a difference in the clarity. i started using poly in my fluval (right before the little bio thingies
) and it works amazingly. it keeps the water
looking like it is polished. however, i believe that the poly
does do some polishing of its own. to a certain extent though. good luck man!