In the perflex EC75 manual Hayward suggests annual acid cleaning with a 1-1 ratio of water to a 20% Muriatic Acid solution.
My question is: Dothey mean a 20 Baum Muriatic solution (approximately 31%). Or do they mean a 20% Muriatic solution.
No one sells 20% Muriatic that I can find, so I'm...