I had two 54 corners full of rock. Sold one setup without the rock and started the other one up again. I had a lot of rock in there - but just re-aquascaped and have a good amount of rock, different sizes and types that I can part with. Haven't weighed it but I would guess at least 40 lbs. I am looking for all those things a newer setup needs - cleaning crew, eg emerald crabs, hermits, variety of snails maybe some softie frags/blue/purple shrooms. I could REALLY use some purple corraline, loose or on a rock to get my rocks seeded too. Or maybe a tunze nano or other flow device.