Clean Gravel

When used for the first time, gravel should be washed thoroughly. Simply rinse clean water through it until the water comes out clear (tap water is fine). For example, put the gravel in a bucket of water, fill it with water, and churn the gravel up. Drain the water and repeat the procedure until the water remains clear. Before using gravel of unknown origin (e.g., not purchased at a fish store), you may want to boil it for 15 minutes to kill unwanted bacteria.