Can anyone suggest a chemical method to clean the tile and grout on the waterline of a gunnite/plaster IG pool?
I see phosphoric acid in one form or another for bathroom use. I'm looking for an industrial-grade product that can be brushed or sprayed on. 'm guessing this is calcium in some form - is there a chemical with really strong affiliation for calcium?
I'm not going to use acid - the strength I want would be HAZMAT, and I don't need the hassle.
Media blasting would be fine - if I had commercial grade equipment, but I don't, and I'm not paying $4/ft to have someone who may or may not have the proper equipment and media and/or competence to use them.
Please say someone has come up with a simple chemical system. Pool will be dry if necessary.