Clean Hot Tub Water, Without the Guesswork

Both work well — bromine has a gentler smell and stays more stable in warm water, while chlorine acts faster and is generally less expensive. Whichever you choose, stick with it consistently rather than switching back and forth, since mixing sanitizer types can cause issues.

Test before every use, or at minimum a few times a week. Because a spa holds so much less water than a pool, levels can shift quickly, especially after heavy use.

Foam is almost always caused by body oils, lotions, and detergent residue building up in the water. A defoamer clears it in the moment, but an enzyme product used regularly stops it from coming back by breaking those oils down before they accumulate.

Generally yes, as long as you're matching the actual chemical type rather than the brand name — many products are sold under different names by different companies but contain the same active ingredient. Never physically mix chemicals together before adding them to the water, though.

Most hot tubs need a full drain and refill every 3-4 months, sooner with heavier or more frequent use. Dissolved solids build up over time in a way no amount of chemicals can fully correct, so a fresh fill is the reset.

Wait times vary by product — most balancers and sanitizers clear within 15-20 minutes with the jets running, while shock treatments typically need longer. Always check the product label, and test before soaking if you're unsure.