[mike31154]

77 gallon Hagen running sumpless since January 2007. I used to run a canister as well, but after they developed leaks & with maintenance issues I finally ceased that scenario. While running a canister, I considered it as a mini sump of sorts. I don't get the nitrate factory thing, if the canister doesn't produce nitrates & your stocking hasn't changed, something else such as the live rock has to take up the slack. In any case, if running a canister, it's probably best to leave it empty of any conventional filtration media. A bag of carbon is pretty much all I had in there before finally taking it offline. It certainly developed quite a coating of benthic critters, which are generally considered beneficial for filtering nasties out of your water. Nitrate level of 10 is not that bad, especially in a younger tank. If green hair algae isn't at nuisance levels, I wouldn't be too concerned.

Your water change & filter maintenance routine should keep the system in pretty good shape. What kind of power heads are you running? Adequate flow is one of the best ways to keep things stirred up & prevent build up of crud that leads to issues down the road. Even if you don't have finicky sps coral, I've found strong flow with minimal dead spots is a good thing, provided you're not tearing the flesh off your softies.