50 lbs a little more, about 80 lbs of LS. Had an accident with a large piece of rock, wanted to trim a little off the edges but instead knocked it down the stairs shattering it. Gonna add some more rock in the near future, waiting for my LFS to get a piece of rock in for me and cure it for me too. I adopted the clam from the LFS it was in a tank with normal flo lighting and was placed in a spot where it didn't look like it was getting any food or anywhere near the light it needed. I figured it would have a better shot at life in my tank then in the tank it was in. The tank it was suposed to be in crashed the day before and was apart when the delivery came in. It looks nice reacts to my hand when it comes close to the tank and when I switch the lights on and off. I am spot feeding it mysis and phyto and I have it placed about 6 inches from the lights.