From what I've seen, it seems to come usually from someone wearing a suit or something that has residual soap or phosphates in it. Ours had the same problem after my daughter had a few friends over, the next morning it was solid foam to the lid. Never wash a swimsuit in laundry soap (there's no reason to.) Just rinse and hang dry, I prefer wearing swim briefs because they dry ten times faster than long shorts. Hope this helps.
Too Much Foam In The Hot Tub
in Hot Tub Water Chemistry
Posted
From what I've seen, it seems to come usually from someone wearing a suit or something that has residual soap or phosphates in it. Ours had the same problem after my daughter had a few friends over, the next morning it was solid foam to the lid. Never wash a swimsuit in laundry soap (there's no reason to.) Just rinse and hang dry, I prefer wearing swim briefs because they dry ten times faster than long shorts. Hope this helps.