Purifying System (BLEACH)

[Pescador]

As per Moe's book 1 cup per 20 gals solution of pure unscented bleach is fine to use to kill algae on non porous surfaces. Let soak, rinse thoroughly, air dry and add a chlorine removing water conditioner to the tank and rinse again. If your still not sure you can check for residual chlorine with an OTO swimming pool test kit.

Vinegar is still a lot better at removing mineral deposits.