Why is my hot tub water foamy?

Do you ever open your hot tub cover, ready to sit back, soak, and relax, only to discover foamy water? What’s the deal? It’s a common problem for hot tub owners, and although it can be a nuisance, there’s a simple solution. 

Causes of hot tub foam

Personal care products

Personal care products are one of the most common causes of hot tub foam. Things like lotions, cosmetics, deodorant, natural body oils and dirt can accumulate and turn into foam or a scum ring. Laundry detergent residual in swimwear can also cause foaming. This is more likely to happen when there are more people in your hot tub if you have a party, for example (high bather load).

The solution?

If you can, shower before you use the hot tub to avoid transferring any personal care products into the water. You can also consider washing your bathing suits separately with a mild detergent to prevent buildup in your hot tub water. Shock your hot tub after every big party (or even small gathering) and routinely (at least once a week).

organic waste

Another cause of hot tub foam is organic waste that your filtration system cannot filter out. Organic matter includes things like leaves and debris, grass clippings, and twigs, among other things. Some organic matter is prone to causing foamy water as it breaks down in the filter.

The solution?

Rinse and clean the filter and shock the water.

chemical imbalance: sanitizer levels

Inappropriate disinfection can cause foaming water.

The solution?

Make sure your sanitizer level (chlorine or bromine) is at the recommended level to avoid cloudy or foamy water. Sanitizer keeps the water balanced and free from bacteria and algae.

chemical imbalance: ph levels

Cloudy or foamy hot tub water could indicate that your pH balance is off. A high pH level is much more likely to cause foam directly than a low pH. 

The solution?

Make sure to keep your pH levels around 7.2-7.8 ppm to avoid foaming. 

chemical imbalance: calcium hardness

Low calcium hardness can also cause foamy hot tub water. Poorly balanced water reduces the surface tension of water and can amplify other potential issues (like damaging your hot tub equipment).

The solution?

Adjusting these parameters will help correct the problem.

From a water balance perspective, it is essential to have your water tested regularly. You can also buy quality products to ensure your hot tub water stays clean, clear, and under control!


Come into Buds to get your water tested. We will have the best solution for you!