Planted Tank Guru
Join Date: Jul 2010
Location: British Columbia, Canada
For superior water clarity you can't do much better than what you're presently doing, bloodworm, i.e. using filter floss and Purigen, except to add a fine mesh pre-filter on your intake(s), as creekbottom has suggested.
But you also need to pay attention to proper maintenance of these items, i.e. cleansing/replacement/re-charging, for maximum efficiency.
That means re-charging the Purigen about every 3 weeks, when it just turns somewhat brown - don't leave it until it gets almost black.
And filter floss, double-layered (no more than that or it will tend to slow up your filter flow and posssibly clog it), should be tossed and replaced with new floss every second week.
The fluval Edge pre-filters do an excellent job, but here again, they need to be used properly - they should be rinsed well every 2nd or 3rd day, or they'll accumulate too much crud and lose effectiveness as well as potentially clogging up the filter. (This takes but a minute).
One final note: those 3 items will also be well assisted in purifying, clarifying, and polishing, by the use of a UV sterilizer, and reasonably good water flow throughout the tank, using a circulation pump if need be.