- Fill a bucket or sink with hot water.
- Add ¼ cup of salt for each gallon of water. Put the rocks in the container, and let them soak for 30 minutes.
- Take the rocks out of the bucket, and rinse them under warm running water. Rinse for a minimum of one minute to ensure that all traces of salt are washed away. Residual salt may affect the pH level of aquarium water.
- Scrub the rocks with a stiff-bristle nylon brush. Using clean water, rinse any remaining algae off the rocks.
- Return the rocks to your aquarium.
Things You Will Need
- Bucket -- optional
- Hot water
- Stiff-bristle brush
- If the rocks are along the edge of a pond, pour hot water over them and scrub them with a stiff-bristle metal brush. The algae should be easy to remove.