I've been fighting it for a while now. I've increased water changes to 30%weekly, increased skimming, I change the GFO every few weeks, reduced feedings. Every week I siphon the sand and sump. I noticed a slight difference, but then it started growing back. I pull out a few pounds of it every week. The fresh ro water tests 0 phosphate, but the salt water tests .25, even after the gfo. The tank is just over a year old. Should I be using more GFO?
