Derby Ducks® Floating Chlorinator - Fun to have in your pool, but useful as well! Our above-ground model holds up to three (3) 3" Chlorine Tablets in a detachable basket. It also features an adjustable flow rate, so you can control the amount of chemicals being released into your swimming pool. The larger above-ground model holds up to six (6) 3" Chlorine Tablets and tilts when it needs refilling (check your chlorine level first). Features a childproof lock, expandable basket, and adjustable flow rate. For use in pools over 7500 gallons.