I recently "inherited" about 100 lbs of nice aquarium limestone. Every single piece is half dark green though. I have heard you can mix bleach with water and soak the rocks and then let them sit out in the sun, but I wanted to double check if that would be safe for fish and if that would do anything. Also, I am certainly open to any other ideas for removing this algae. Thanks! P.S. If the bleach thing works. How much bleach should I put in per 10 gallons?