BioGuard Anti Foam 1 Qt. | Pool & Spa Defoamer

BioGuard Anti Foam collapses foam in pools, spas, hot tubs, and ornamental fountains within seconds of application. It's a fast, targeted fix for a problem that tends to appear at the worst possible moment — usually about ten minutes before guests arrive.

Foam happens when something in the water reduces its surface tension enough that agitation produces bubbles that don't pop. Body oils, lotions, sunscreen, shampoo and soap residue, and detergent left in swimwear all do this. So do a few things pool owners don't connect to foam at all: soft water with low calcium hardness, an overdose of a quat-based algaecide, and filter cleaner that made its way back into the pool instead of going to waste. Add jets, a waterfall, or an aerated return, and the water starts producing a head of foam it can't clear.

Anti Foam breaks that surface film and the bubbles collapse. The effect is essentially immediate, and it can be reapplied as many times as needed on heavy buildup without adverse reactions. It's pH neutral, so knocking down foam doesn't move your balance and trigger a second correction. It works with every sanitizer type and on every pool surface, and swimming can resume shortly after application.

One further note worth understanding before you buy: Anti Foam treats the symptom, not the cause. That's genuinely useful when you need clear water in the next five minutes. But foam that keeps returning is telling you something about the water, and the fix for that lives elsewhere. Both uses are covered below.