Are you using RO
water? My tap water measures 5-10 nitrates! Makes it hard to ever get to 0! Check the level of your source water for some clues...
I have practically the same setup, but with an emporer 400 biowheel. Anyway, take out the biowheels maybe a week apart to give the tank time to adjust to the bioload. Then just run it for carbon / mechanical purposes as needed. Be sure to wash the filter packs in fw
every week or so, this way they won't become biofilters! I actually run mine on a timer while the lights are on, it does a nice job of surface agitation / oxygenating the tank, not to mention keeping water crystal clear or cleaning up after a water change. I do run a skimmer, but I definately think the filter benefits the tank.
Several water changes after I removed the biowheels and moved to RO
my nitrates have been in the 5 range. This should work for you.