to maximise the enjoyment of your spa or hot tub water,it is essential to keep your filters clean. clean your filters at least once a week. to assist you with this, we have a fast acting, environmentally friendly 'fizz' tablet to keep your filter in optimum condition. unlike traditional filter cleaning solutions which need a massive 24 hours soaking period, the aquafinesse filter cleaning tablets whizz through your filters in just one hour! important: good water quality is dependent on a clean filter. each box contains 20 individually wrapped filter cleaning tablets.