My pH is in the 8-8.5 range (I need to get a better test kit), salinity is 1.025, temp is 78, nitrate and nitrites are fine and calcium is around 370-380. I have the brain up in the tank, in fact it was after I figured out it should be down in the substrate and I moved it there that it stopped opening up after a few days. I tried target feeding but of course the shrimp, fish and crabs all take the food from it. I might have to set it back on the substrate and try to cover it like you did.