Just want to share my expirience. I decided to try and work without the GFO reactor. Its too much work, gets clogged often causing phosphate spikes, and it eliminates some trace elements. Also, I have been dosing TM NP Bactobalance only to realize that it contains Nitrate and phosphate, I replaced it with Elimi NP (I dose 2 mls to a 110g tank). After removong the GFO reactor, the PO4 concentration went up from below 0.1 to 0.21 in 4 days. Tank is mostly LPS with 13 adult fish and about 30 baby Bengai cardinals in the refuge. Fish are heavily fed but parameters were rather stable around 0-10 ppm for NO3 and 0.03-0.1 for phosphate. I also dose KZ spongepower to promote sponges growth. Tothis day corals seem to like the change