Foam comes from soap, lotions and detergent left in swimsuits, and from water that has been in the tub too long. Jets whip it up.
What to do
- Shower before soaking and rinse swimsuits in plain water, without detergent.
- Test calcium hardness. Soft water foams more: keep it between 100 and 250 ppm.
- Anti-foam sprays hide foam for a day; they don’t remove the cause.
- If foam keeps coming back, drain and refill. Many owners do it every 3–4 months.