That could depend on your on which part of the country in which you live and the make up of the water. Meaning, is it alkaline or acidic? The best possible short answer may be to use the best quality available. Do not use cheap grade chemicals.
chlorine, ph+, ph-, alkalinity, calcium, algaecide, and clarifier are your basics ............. Okay why is this flagged. supervisors are gay .............some sanitisers are; sodium hypochlorite,...