U.S. Pool Supply Floating Spa, Hot Tub & Small Pool Chlorine and Bromine Dispenser

Sanitizer is used up all week, not just while people soak. A floater spreads the dose out: tablets sit in the slotted tube below the float and dissolve slowly, and a simple turn lets more or less water through. This one is built for spas and small pools, takes 1 in (2.5 cm) tablets and has 13 flow settings.

The listing gives neither its size nor how many tablets it holds, and no floater can tell you what the water needs – that is the test strip’s job. Set it, test a day or two later and adjust one step at a time. Some tub makers advise against floaters or against certain tablets, so check the manual first.

Tip: Take the floater out while anyone is in the tub and set it in a bucket out of reach of children – never on the cover or the deck, where it can drip concentrated sanitizer.