Tony,
Ok, working off some reading I've done on this topic - not first hand (I prefer coil based denitrators myself). Sounds like your through-put is way too fast, crank it WAY down until you start seeing effluent output with 0 nitrite / 0 nitrate (or get stunk outta the house - that'd indicate way too slow). Once you get that 0/0 effluent then start bringing up the drip rate slowly.
Definitely check that mag pump you're using for recirc... Although that kicks your cycle back to day 1 again (introduction of too much o2 - supposed to be a low o2 environment), if it's not working up to snuff - the lack of recirc could be causing some problems.
since i'll never find the link again - good rc thread: http://reefcentral.com/forums/showth...hreadid=752497