HSG282, the HSE's guidance for business hot tubs - holiday lets, B&Bs and holiday parks - expects the water to be tested at least twice a day, kept properly sanitised, and shocked as part of the water change between guests. This kit
Twice-daily water checks with a written record for your log
Keeps chlorine in the 3-5 mg/l band HSG282 expects
Shock dose for the water change between guest stays