Sani Marc 30-07185-04 4L Summer Smiles Klean Surface Ultra All Purpose Cleaner is an organic acid solution specially developed for pools. It efficiently cleans concrete, bricks, stones and ceramic while being safe for users and the environment. Klean Surface Ultra improves the adherence of paint on concrete, efficiently eliminates efflorescence salts and limescale deposits, and lowers PH levels and total alkalinity levels in pool water