Question... Can I treat my flourite with peroxide to get rid of algae. Want to sterilize my whole system. Have black bushy stuff that sneaked in with a new plant... Scared flourite will disintegrate or absorb the stuff and poison the tank later.
With no fish or other fauna in the tank you can use Excel at 10X dosage to kill BBA. Or drain off most of the tank water and dose just the substrate and remaining water with an overdose of Excel. Hydrogen peroxide is certainly a lot cheaper, and not nearly as toxic either.