Foaming in hot tubs and spas is a problem that every spa owner will have at one time or another. Even if you take great care of your spa, always ensuring good sanitation and filtration, foamy spa water can become an issue, so don’t be embarrassed if it happens to you! A little bit of foam is normal, especially if you run a bubble blower, but if there’s more than a thin layer…
You could drain the hot tub, and refill with fresh water, but that won’t always fix the problem. Read on for some fresh thoughts about foamy hot tubs and spas – and how to fix the foam!
What Causes Hot Tub Foaming?
- Jokesters adding soap to the hot tub
- Soft water, Calcium Hardness too low
- High pH and Total Alkalinity levels
- Soaps on skin and swim wear
- Cosmetics and hair care products
- Certain low grade spa chemicals
- Body oil or oils from foods
How to Control a Foamy Hot Tub
The fast way to fix a foamy spa is to use anti-foam agents. Just spray a small amount over the surface of the water. The silicone based chemical immediately spreads over the entire surface, and destabilizes soaps and foams, popping all of the tiny bubbles!
A better way to control hot tub foam is to not have it in the first place. Using defoamers or anti-foam is just a temporary fix. It doesn’t do anything to solve the problem of how the soaps and oils got into the hot tub in the first place.
How to Prevent Hot Tub Foam
- Balance the Water – pH, Alkalinity, Calcium.
- Maintain a constant sanitizer residual.
- Shower thoroughly before using spa.
- Keep your head above water at all times.
- Observe spa capacity limits, and limit soak time.
- Rinse bathing suits washed with soap before use.
- Replace your spa filter regularly.
- Replace your spa water regularly.
- Add sanitizer support, like minerals or ozone.
Spa Water Balance and Foamy Water
What’s water balance got to do with it? Nearly everything it seems; when pH and Alkalinity are high, and Hardness levels are low, the water becomes “slippery” and fats, oils and dirt combine into soaps. Soap also enters the spa on swimwear, skin or hair and finds it easy to multiply in a high pH, soft water environment.
Good water balance also allows your sanitizers to work more effectively, reducing contaminants and breaking up oils and scum that can become components of foamy water. Soap scum, or a bathtub ring around the spa is another result of poor water balance.
- Add Calcium Increaser if your Calcium Hardness level is less than 200 ppm
- Add Alkalinity Increaser if your Total Alkalinity level is less than 100 ppm
- Add pH Up or pH Down to keep pH level between 7.4 – 7.6
Using Anti-Foam in a Spa or Hot Tub
- Balance chemistry first, for best results.
- Clean or replace spa cartridge filter.
- Follow dosage directions carefully.
- Re-dose with Anti-Foam only after 8 hours.
- Lock it up, to prevent re-dosing by others.
Cloudy Water and Hot Tub Foam
The often go hand in hand, cloudy water and foamy water, and you’ll rarely have one without the other. In fact, may of the conditions and symptoms are the same, and one can cause the other as well. The same tips listed to prevent hot tub foam apply to cloudy hot tub water.
Adding air into the jets, passive air or pumped air (blower) will exacerbate a foaming problem, as it will entrain air (tiny bubbles) into the water, giving an appearance of cloudy water, but also whipping up the water into a foamy froth.
Chemicals that Cause Foam in Hot Tub
- Low grade bromine or chlorine products
- Low grade algaecides (10%)
- Biguanide sanitizer chemical
- Household cleaners or soaps
Biofilm and Hot Tub Foaming
We’ve reported on Biofilm in Hot Tubs many times on this blog. In cases where hidden biofilm is allowed to build-up, they can provide and endless source of oily scum that can easily turn into a foaming problem. If you’ve tried everything else to reduce spa foam, but it keeps returning, consider using a product to strip the pipes and equipment of any biofilm. Spa Purge or Jet Clean are two good products. Use annually to prevent new colony formation.
How much Foam is too much Foam?
Just about every spa will have some small amount of foam, and even on well maintained spas, you may notice foam beginning to develop as your spa water gets older. Yes, foamy hot tub water can be a sign that it is time to change the spa water.
When there is more than an inch of foam however, it begins to get annoying, but the larger reason to deal with spa foam is that foamy water becomes an ideal transport medium for bacteria, emulsifying it to the surface where it can be more readily absorbed by bathers.
FOAM PARTY IN A HOT TUB
If you were a victim of a joke, or have a teenager who thought Foam Party in a Hot Tub would be a good idea – drain the hot tub, flush the lines out several times and clean all surfaces before it’s refilled. After refilling, balance and shock the water. If you still have soap residue, use Jet Clean or a similar Purge chemical to clean the pipes.
Foam hot tub parties may be fun, but you really need to clean well afterwards, and there may still be soap residue after draining the spa several times. Plus, it can be unsafe – so do yourself a favor and just say no to hot tub foam parties!