Nice , I started off with about 20 spheres in my 750 and first icp test was slightly elevated and I panicked . I have 140lbs of rock and a not so heavy bioload so I just took it out. Glad to see that with your amount everything is still all good !!I just conducted my first ICP test and it was reported that Aluminum was present, but well within range. I am pretty happy with that as I have A LOT of MarinePure (blocks and spheres) in my system.