Whether you're a new or seasoned spa owner, there's not much relaxation appeal to foamy water. In this guide, we take a look at the main causes of foamy spa water and how to treat it. Unlike soaps and shampoos that you use to create your traditional bubble bath, foamy spa water is very different.
Foamy spa water shares many similarities with seafoam, with only minor differences in their chemical composition. Both spa and sea foam require three (3) things to develop: air, water and surfactants. Surfactants are sticky molecules that decrease the surface tension of liquids, making it easier for substances such as water and other contaminants to mix. All spas are made up of chemicals, detergents, proteins, salts and other compounds, many of which are surfactants. Even a properly maintained spa with ideal water chemistry will contain surfactants, which will cause foamy spa water if left untreated. The more surfactants you have, the more bubbles will form, eventually stacking together to create a foamy layer.
A properly maintained spa will be evenly mixed with a combination of sanitising chemicals and calcium, both of which help to neutralise surfactants. The main surfactants your spa will be exposed to are:
The main offenders include makeup, shampoos, hair styling gels and mousses, hairsprays, sunscreens, moisturisers, conditioners and deodorants. These products will cause your spa's chemicals to react, causing foamy and cloudy byproducts. As we mentioned above, the more surfactants in your spa, the higher the chances of foam appearing.
Humans go through each day unknowingly collecting residual and non-residual contaminants. These include body oils, sweat and dead skin cells, all of which put your sanitising chemicals to work and can eventually cause foamy water if your spa chemicals are not balanced after use.
Laundry detergent and soap are primary offenders. While important to wash your swimwear, be mindful of remaining detergent within the fabric.
Beverages, both alcohol and non-alcoholic contain sugars that can cause foamy spa water. We recommend keeping drinks away from your spa for safe measures.
Foamy water is a common spa issue and not something to stress about. With a few simple steps, you can have your spa back to full health.
The first thing you should do is test your spa water. The main things you're looking for is alkalinity, pH and calcium hardness levels, as well as total dissolved solids (TDS) - these are your surfactants. Determining your water chemistry at the time of seeing foamy water will also help you to understand the cause and prevent a foamy spa in the future.
Alkalinity: Another way to say water is basic is to call it alkaline. When your hot tub water has alkalinity higher than 150ppm, it begins to form scale. It also cannot keep pH stable, compounding all the issues that may cause foamy water. The ideal level is 80-120ppm.
pH: Your spa water is too basic if the pH is higher than 7.6. When this happens, you'll wind up with two problems that cause cloudiness: scale formation and ineffective sanitising. You may need to use a pH decreaser to get things back to normal. The ideal level is between 7.4 and 7.6.
Calcium hardness: Ideally, your spa's calcium hardness will be between 150-400ppm. If your levels are too high, you'll see scale build-up and foaminess.
After you’ve tested your water and documented your water chemistry, the most effective way to remove foam is to completely drain, clean and refill your spa. At this stage, it's also a good idea to check for any faults in your spa's system, as these can also be the cause of cloudy and foamy water.
Once you’ve drained, cleaned, and refilled your spa, test the water again, adding chemicals where required. If your water chemistry is in the ideal range, let your spa circulate the water for at least 12-24 hours. When the circulation is complete, test the water one more time to make sure it’s ready for bathers.
If you would like professional assistance balancing your spa, speak to your local pool professional.