Why Is My Hot Tub Foaming? Common Causes and Fixes

Foam in your hot tub might seem harmless, but it’s often a sign that something isn’t right with your water chemistry or maintenance routine. While a little foam might not ruin your soak, excessive or persistent foam can indicate underlying issues that need attention. Let’s dive into the common causes of hot tub foam and how to get rid of it for good.

What Causes Hot Tub Foam?

Foam forms when contaminants in the water create surface tension, allowing air to mix in and create bubbles. Here are the most common culprits:

• Body Lotions and Oils: Personal care products like lotions, sunscreen, and body oils can build up in the water and lead to foam.
• Soap Residue: Residual soap from bathing suits that haven’t been thoroughly rinsed can mix with the water, creating foam.
• Low Calcium Hardness: If the water is too soft (low calcium hardness), it can encourage foaming.
• Detergent Residue: Laundry detergents left on towels or swimsuits can dissolve in the water and cause foaming.
• Old or Unbalanced Water: Water that hasn’t been changed in a while or is unbalanced can contribute to foam buildup.

How to Get Rid of Hot Tub Foam

Once foam appears, you’ll want to act quickly to restore the water to its proper condition. Here’s how:

1. Skim the Foam

Start by physically removing foam from the surface using a skimmer net. While this doesn’t address the root cause, it helps reduce foam temporarily.

2. Balance Your Water Chemistry

Test your water using test strips and ensure the following levels are within range:

• pH: 7.2 - 7.8
• Alkalinity: 80 - 120 ppm
• Calcium Hardness: 150 - 250 ppm

Low calcium hardness is a common contributor to foam. Use a calcium increaser to raise levels if needed.

3. Shock the Water

Perform a shock treatment to eliminate organic contaminants like body oils, sunscreen, and soap residues. Choose a chlorine or non-chlorine shock depending on your sanitizer system.

4. Clean the Filters

Foam-causing contaminants often accumulate in your filters. Remove the filters and rinse them thoroughly with a garden hose. For a deeper clean, soak them in a filter cleaning solution.

5. Drain and Refill

If the foam persists after trying the steps above, it might be time to drain and refill your hot tub. Fresh water is the best solution for heavily contaminated water.

Preventing Hot Tub Foam

Prevention is key to keeping your water foam-free. Follow these tips to avoid foam buildup:

• Rinse Before Soaking: Shower before entering the hot tub to remove lotions, oils, and dirt from your skin.
• Rinse Swimwear: Always rinse swimsuits thoroughly after washing to remove soap or detergent residue.
• Use Quality Chemicals: Invest in high-quality hot tub chemicals to maintain balanced and clean water.
• Regular Maintenance: Test and balance your water weekly, clean your filters, and shock the water as needed.

For all your hot tub maintenance needs, check out our Hot Tub Care Collection.

Final Thoughts

Hot tub foam is usually a sign of water imbalance or contamination, but the good news is it’s preventable with regular maintenance and care. By following these tips, you can enjoy foam-free, crystal-clear water every time you soak.

Explore our Hot Tub Care Collection for products designed to keep your spa water clean and inviting.