a 15-20 times total tank turnover is optimal for good oxygen exchange and to keep the tank well circulated i.e. the 800-1000 total GPH
figure. You want at least two PH in the 300+ GPH
range like two Maxi-Jet 1200 or two Hydor Koralia Water Circulation Pump
(2) like Scott had suggested on your other post.
One canister is more then enough and should only be used for circulation and infrequent chemical usage and cleaned weekly or every other week.
is one of the biggest expenses next to quality lighting and skimmer. I wouldn't wait too long, it's well worth the investment.