I just recently have started dosing nopox as well, and I run red sea carbon in my sump....I noticed that since dosing the nopox one or two heads on two separate ZOA's have started to almost like ball up and shrink a little...I can't really confirm it was the nopox but my nitrates went from 10 ppm to 2.5-5ppm. I'm cutting back on the nopox and it seems to be helping, aswell as good husbandry. My ZOA's are under t5s and I gotta say they love them. I've had them under LED and they just don't like them as much....also, I would consider dipping all your corals that you put into your tank. You really wouldnt believe what pests and kinds of crap come off of them, plus you never know what was in the other tank they came from!! Do you have pics? And how are your mag, cal, and alk? Stable? While ZOA's like a little dirtier water (not too dirty) I've also found that every week or so I'll take my turkey baster and gently blow all the crud out from in between them! Helps alot