An easier way of maintaining chlorine levels in your pool water, 200g Chlorine Tablets are placed in the skimmer, floating dispenser or chlorine feeder (trichlorinator). When dosed via the skimmer the tablet(s) will dissolve slowly over a 3 to 4 day period, the rate at which they dissolve will vary depending upon water flow and temperature. They have a high level of available chlorine and contain chlorine stabiliser.