BIO-Balls do not require replacement unless damaged or destroyed. In the event of
excessive buildup, you may gently rinse with water from an established aquarium, if
desired. Do not clean with soaps or abrasives and never rinse with tap water.
bio balls by lukystif from rochester, ny.08/30/2012
I like them, I was looking fo k-1, but these little balls float, have tons of surface area, and if you have the filter area , and air injected , they will bounce around , float , grow benefitial bacteria probrobly better then anything on the market.