To anyone wanting to convert to sand, do it! Its a great change. Wash the sand extremely well, even if it says its been washed, it still has dust in it. To wash it put it in a bucket with a hose running water into the bottom of the bucket, moving clean water up through the sand, and out of the bucket. Dump it in the tank when its clean, even it out, and fill it up. The legend about it messing impellers and other parts up are fake, the only way it could mess something up is if you dumped sand into the intake. It will be foggy when you first put it in, but goes away over night. I hope this helps anyone. And a reply to Steg22, I wouldn't do it with fish in. The particles may harm the fish. Why do you need to replace the sand? Color? Just stir the sand and it should turn back to its natural color.