need help cleaning old rock.

firefightered · Feb 12, 2012

I just recieve a bucket of "old reef rock" and its dirty. It has been sitting under my neighbor's porch for a few years. I would like to clean this stuff up and use it but not sure how to do it safely. I'm guessing.... Wash the rock as good as possible with a garden hose and brush. Put rock in lg. bucket for a few days and do it again. Clean bucket and add salt water, live rock piece, heater and pump. Let cycle for ? time. Any other suggestions?

Tomoko Schum · Feb 12, 2012

Hi Ed,

You can soak your rocks overnight with 10% bleach to get rid of any living or dead organisms. Then, rinse the rocks with water and dechlorinating solution. After that, rinse your rocks with 10% muriatic acid solution for a short time to remove the PO4 surface layer. The acid is a separate step to remove any phosphate deposits on the live rock by dissolving away the outer layer of the rock. Mixing bleach and hydrochloric acid/muriatic acid is not good.

Search the Chemistry forum of "the other board", the one that cannot be named, for Bleach vs Acid thread. You find the information you are looking for in the thread. Make sure that you read the comments by Dr. Randy Holmes-Farley (he's a renound chemist.)

Dave3112 · Feb 12, 2012

Tomoko Schum said:
Hi Ed,

You can soak your rocks overnight with 10% bleach to get rid of any living or dead organisms. Then, rinse the rocks with water and dechlorinating solution. After that, rinse your rocks with 10% muriatic acid solution for a short time to remove the PO4 surface layer. The acid is a separate step to remove any phosphate deposits on the live rock by dissolving away the outer layer of the rock. Mixing bleach and hydrochloric acid/muriatic acid is not good.

Search the Chemistry forum of "the other board", the one that cannot be named, for Bleach vs Acid thread. You find the information you are looking for in the thread. Make sure that you read the comments by Dr. Randy Holmes-Farley (he's a renound chemist.)

++1 Great advice as usual Tomoko!

JSB · Feb 12, 2012

If there is a lot of large organic materials on the rock, I think I would start with a pressure washer, and then follow Tomoko's plan. If it is fairly clean, though, the pressure washer is not necessary.

hardimanm · Feb 12, 2012

I have also heard that after a good scrubbing just leaving it outside to dry in the sun for a while and rotating it will help bleach and kill anything that might be on it. But as it was under a porch i would def use some bleach just to be safe