I had a surplus of LR in a 30G with a bucket of sand, heater and pump to always have running and the sand bucket had a metal stint in the bottom that rusted out. I didn't know it was in there, lesson learned to check thoroughly! I tossed the contents all but the pump and am recycling the 30g brute as a recycling container! The pump is clean except for a rust stain I cannot scrub out. Is this safe to use for mixing water? I don't want to chance anything before asking you guys, old post on the web in general say its fine, but I trust you over them. Thanks!