Regular$ 469 SALE $ 399!!! Automatic Bromine Salt Water Generator For Spa Sanitizing Domestic. -A maximum of 2000litres of water can be treated with one in.clear unit. -Maximum output of hypobromus acid equivalent to 0.04 Kg of free available bromine per day. -For spas, a range of 3-5ppm of free available bromine must be maintained.