On Drs. Foster & Smith, they have this thing called the mag-flip and supposedly it gets coraline algae off. I was going to order it but apparently my order didn't go in "correctly." So I never got it. :(

Mainly because shipping is $9.99 and the product itself is $39.99.
They even have a video on it:

http://www.drsfostersmith.com/produc...m?pcatid=19866