Thanks guys. I haven't been watching the tank that closely for the past few days, getting ready for the Pinewood Derby-lol. I didn't notice tissue recession Monday. Trident number have been consistent. I'll admit there are some sps I haven't had luck with, others do great. I thought my occasional losses were a nutrient issue, no3 po4 too low but I've added an Achilles and Tomini so I have been feeding more nori to prevent food aggression. Past failures I related to Vibrant dosing, but that was trashed months ago. Time for some testing. If this was simple I may have gotten bored of this hobby years ago.