I'm not sure you've ever dealt with bryopsis before. I have an oversized skimmer, high capacity gfo changed weekly, zero phos or nitrates, twice a week i pull out the bryopsis and blow off the rocks and replace the water with freshly made stuff. I can't even get my chaeto to grow anymore, the bubble algae that used to be in there is completely gone, there is no other algae in my tank. This stuff does not care if you run a ULNS system, i would take just about any other algae problem over this as most others are an easy fix with correcting nutrients.