We tested three common fixes for hot tub foam. See which method worked, how long results lasted, and what to avoid.
Foam is the hot tub owner’s nemesis. It looks bad, feels worse, and usually shows up right before guests arrive. We put three fixes to the test to see which one actually solved the problem.
The Setup
The spa had light foam after normal use. Water was balanced (pH 7.6, TA 90 ppm, sanitizer in range). Jets were run for 20 minutes to trigger foam.
Fix #1: Foam Reducer
Result: Worked instantly but lasted only 24 hours. Foam returned with the next soak.
Fix #2: Filter Deep Clean
Result: Improved clarity slightly but didn’t eliminate foam. Soap residue likely remained in the water.
Fix #3: Partial Drain and Refill
Result: Clear within hours and stayed foam-free for weeks. Best long-term solution.
The Winner
Partial drain and refill. Foam reducers are fine for emergencies, but lasting results come from reducing contaminants at the source.
More long-term maintenance routines live in Tub Time. For water chemistry refreshers, explore Pool Lessons. For safe soaking info, see the CDC spa water resources.
FAQ
Will a full drain fix foam better than partial
Yes, but even a 50% drain usually reduces contaminants enough to make a difference.
Can enzymes help
Yes, they can help break down organics that lead to foam, but they don’t replace proper maintenance.