Bought a Marineland canister filter(c-360) rated for up to 100 gal tanks , put it in my 55 gal comm tank ian its doing a fabulous job Ive never saw my tank so far... I mean the tank is crystal clean.. So I bought Penn plex 700 rated for 260 gal tanks I think so far Im not impressed,its been on my 100 gal fof 2 days and no improvements yet..In my 100 gal I have 1 poly and 4 other birchirs ,3 peacocks and 3 other fish none of them are bigger than 10 inchs,,, so the bio load shouldnt be all that bad..I will take some pics tonite and post them tomorrow and acouple of days after to see if there are aany improvements..