Hi Saltguy! So you have nitrate problems huh? That sucks...Hopefully we all can help...
For starters are how old is the tank and are you using ro/di water? You said you are using 2 powerheads...Which ones and how much flow do they produce? If you have deadspots in your tank then that could be part of the problem as when detritus accumulates and sits on your rocks (or wherever) and is not removed, then water quality drops. Are you running a sand bed? If so, is it a dsb, or ssb? Also, how often do you do water changes and how much do you change? Another thing is you said you use an emperor 400 filter. Does it still have the bio-wheel in it? If so, then that can be causing some of the nitrate issues as the bio-wheels only convert ammonia to nitrite and then nitrite to nitrate and it stops there. So you get an accumulation of nitrates as a result of them. Same thing as usuing bio-balls in a wet/dry environment. Also, what are you running in the emperor filter? If carbon, how often do you change it because if it is not changes regularily, then whatever the carbon absorbs, will be leached back into your system once it is exhausted itself. If you are using the cartridge, how often do you clean it or change it? With those floss pads, wastes get trapped in there and if not removed from the system regularily, it will break down and diminish water quality as well. You said you had a 20 gal sump. What's in it? bio-balls, LR, macro-algae etc. Sorry so many questions...The answers to some of these questions may help everyone get a better understanding of your system which will enable us to help you...Best of luck and I hope we can all get you sorted out.
