Thanks for starting this thread and for the comments put forth so far.
I starting running the NPX pellets a week ago after a 45 gallon water change in my 180 mixed reef tank, particularly due to a stubborn nitrate level of about 30 ppm which I have been unable to reduce through vodka dosing (keep forgetting to add). I also have a nominal break out of hair algae which I have been working to restrain.
As several here and at Reef Central suggested, my reactor output goes to my Deltec skimmer water feed. I started with about 2/3 of the bag of 550 ml, or about 350 ml. I did not remove the sponges as Steve Weast suggests, but will do when I add the balance of 200 ml of pellets this weekend.
Thus far, I have seen no negative reaction from my tank inhabitants, which include a large wrasse. I have recognized a decidedly clearer tank however, as well as a "percieved increase" in both polyp extension and coloration of corals, particularly my acans. Whether this is due to the pellets, the water change, or my mental desire to have these pellets transform my tank, I don't know, but so far so good.
I'm looking forward to my test results this weekend and the addition of the balance of the pellets to my reactor.
Mark