If your source water is soft (low CH and TA) and you get enough rain dilution throughout the season (which is entirely possible in SC), then cal-hypo usage is fine. Just keep an eye on CH and pH because cal-hypo is very caustic stuff and will add to your TA as well as CH. The high pH generated in the skimmer will be temporary enough to not be too dangerous BUT you should ensue that you have good flow (run the pump on high speed if it’s a 2-speed or VSP) to ensure fast dissolution. It’s not something I would ever do with acidic forms of chlorine but it’s ok for alkaline sources. Do note though that adding high doses of chlorine into the filter can cause a spike in CC readings if the filter is dirty due to the higher concentration levels of both chlorine and bather waste.
