So I bought my first RBT nem about two weeks ago. It was from a vendor that treats all his nems before sale so he had it for about three weeks before selling it to me. I acclimated it, turned off all flow for about 3 hours and placed it at the bottom of the tank. He walked up the rock about 2" , stayed for 2 days then walked down and crawled in a cave. I left him there for 4 days(very hard to remove) then removed him and placed on tank bottom(I run bare bottom). He immediately opened up, looks healthy, no gaping, bubbles on tentacles. Then started walking again. Every time I uncover, move him back into the light he walks again into cover. I run 4 T5 tubes, 48" long on a standard 75 gal. I can't fathom this being too much light but is it. Flow is a single gyre 350 in the back corner, tank is set up as a peninsula, so flow is around a rock structure centered lengthwise in the tank. Flow is set at random pulse, max 30% so far. I had it at 80% prior to introducing the nem and still had all other softies and LPS happy, no stress. Any ideas are appreciated as I'm new to RBT's, thanks.