What's the best way to clean old Lava Rocks? They are primarily going to be used under my substrate to build hills. I have close to 150 pounds worth of fist size and smaller lava rocks from the old Koi Pond filter setup. We replaced them last year with Bio Balls, but have been sitting outside around the waterfall since we took them out. They were rinsed, but that's about it.
Cleaning old rocks?
- Thread starter Little Soprano
- Start date
Boil them in a pot on the stove for an hour, then put them in a bucket of warm water and scrub them with an old tooth brush.
You could also drop them into a bleach/water mix for 5-10 minutes. 19 parts water to 1 part bleach. Thoroughly rinse and scrub after the soak. Either that or the hot water will work.
