I ran PHOS-BAN for about 5-6 weeks in a Little Fishes Reactor with little drop. Last 3-4 weeks been running PhosGuard. Levels about .1 or under. :joy: I also shortened daylight lighting to 6-7 hours, to combat bad algaes. Water changes every 2-3 weeks. (about 20 %) Cleaned out sand-bed with Vacuum-siphon thing. Really watched feeding so as not to overfeed. Originally thought FLA live rock had something to do with high levels, now that doesn't seem to be the case. I recommend the Reactor, it worked for me , but if you can get good water flow through the media ,go for it.