You’re not alone if you’ve noticed a ring around your hot tub, strange foam, or a slimy buildup. Many of our hot tub customers ask the same question about how to eliminate scum in hot tubs. The gross scum lines create a dirty look and feel.

Your hot tub is not the culprit. In fact, the scum in hot tubs is typically caused by substances we bring in ourselves. Now I’m not calling you dirty or stinky, but lotions, oils, and even detergent residues from our bodies are leading to scum buildup, foam, and those pesky scum lines along the waterline. So let’s get specific about the cause and solutions to Scum Lines.

6 Easy Steps to Get Rid of Scum Lines in Your Hot Tub

Scum lines in your spa are frustrating. With these 6 easy steps, you can keep your water clean, clear, and free from scum. Follow these steps to eliminate hot tub scum, whether it’s brown scum, yellow scum, or green scum.

1. How to Eliminate Scum in Hot Tubs with Clean Water

The first step to eliminate scum in your hot tub is maintaining proper water chemistry, regularly replacing your hot tub water, and properly sanitizing the liner itself. This means emptying and refilling your hot tub every 60-90 days and using a cleaner to clean off the scum while it’s empty to help keep everything as hygienic as possible.

If scum buildup is mild, you may be able to wipe it away or use a cleaning system without emptying the tub entirely.

2. Shower Before Using Your Spa

A major cause of scum in hot tubs is people bringing oils, lotions, deodorants, and hair products. Taking a quick shower before entering your spa will minimize the buildup of scum and other debris. This removes oils, dead skin cells, and other substances that would otherwise contribute to scum lines and ultimately the buildup on the pool’s edge.

3. Shock

Make sure you’re doing a regular shock treatment in your hot tub, particularly if you use your hot tub frequently. If keeps appearing in your water, you might need to boost your sanitizer levels and weekly shock treatments are a great way to do that.

You should also maintain a regular cleaning schedule, which includes draining and scrubbing down your acrylic liner with a non-foaming cleaner before refilling with new water. A key step in eliminating scum is using a quality shock treatment. Check out our premium shock treatments.

4. Green Scum

If your scum is green, this is usually a sign that there is a type of metal in your water. Copper, magnesium, or some other dissolved metal in the water often reacts with bromine and can leave behind a green residue.

To help eliminate the problem? Try a pre-filter so that your fill water will have as little extra metal in it as possible, and you won’t have to do as much post-fill adjusting.

5. Blue/Green Scum

If the scum in your hot tub has a bluish-green tint, your filters are more than likely clogged, torn, or worn out. To keep your water properly sanitized and prevent scum buildup, replace hot tub filters every 1 1/2 to 2 years, depending on maintenance. Clean your filters monthly by spraying them off to ensure efficient water circulation and filtration.

6. Brown Scum

If you have a brown or grey color scum appearing, it could be a mineral like iron reacting in your water chemistry. This can also signal that your pH levels are too high.

Use a pH decreaser to bring your levels down to the 7.2-7.4 range for the best results. Regularly testing and adjusting your pH levels will help eliminate brown scum and maintain clean and clear water.

The Science Behind Scum Buildup

Understanding what causes scum buildup is the first step toward eliminating scum in hot tubs. A gross thing happens when a hot tub gets used frequently. A film builds up on the water that is an accumulation of body oils, grease, and other human byproducts (yuck) that are washed off from people in the spa. Lotions, shampoos, and hair products all add to this problem. This film can often can lead to an unpleasant foam and yellow or brown scum, making your spa experience less enjoyable. Hot Tub buildup results in a nasty-looking scum ring along the entire waterline of your spa.

In the past, people would use soap to try and deal with the water gunk, but overuse of soaps (or surfactants) often leads to foaming and throwing the water chemistry out of whack. The pool industry then set out to develop a serviceable alternative that incorporated enzymes and could be added to the water to break down all the unwanted stuff in and on the water.

This project faced a few difficulties. First, the enzyme had to be in liquid form so that it could be quickly incorporated into the water, and the enzyme that was chosen for its ability to break down oils and greases (lipase enzyme) was not entirely shelf-stable in liquid form. This meant that the enzymes would break down in the bottle before it could ever be used.

The second problem was that doses of traditional sanitizers like chlorine or bromine would destroy the enzymes, so a new form of enzyme-based products was developed that were shelf stable and able to work in the water along with bromine, chlorine, biguanide, ozone, or non-chlorine shocks.

The enzymes now work in conjunction with these sanitizers and actually boost their performance. The enzymes are positively charged to attract oil, organic particles, and any unwanted byproducts in your spa and hot tub. They then bond to these contaminants and dissolve them away to be filtered out of the water.

What are the benefits of using hot tub enzymes?

Untreated contaminants build up quickly in hot tubs, which have a relatively small area of water and high water temperatures. Using a hot tub enzyme treatment will break down the organic waste that can then be filtered out without gumming up the works. Left untreated, contaminants can clog filters and shorten their life cycle.

There are some added benefits to using enzymes in your spa water. Hot tub enzymes also help with chemical smells that traditional sanitizers may cause. They also break down any irritants in the water that may result in eye and skin irritation (usually urine forming chloramines with chlorine in the water).

As an added bonus for anyone who’s earth-conscious, consumers will be glad to know that this product is biodegradable and the only active ingredient in it them is all-natural. Enzymes work very well in spas and hot tubs because the warm water helps to speed up the degradation process. The end product of the process is harmless and there are no residues to build up. It’s a great, natural way to boost your sanitation system.

Conclusion

As someone with over 25 years in the spa and billiard industry, I’ve seen firsthand how the right care can make a huge difference in your hot tub experience. At Take A Break Spas, we’ve earned several awards for customer service and have been recognized as one of the best local spa companies.  I’m proud of our dedicated team, and we are always here to help with expert advice on how to eliminate scum in hot tubs. If you ever need assistance with anything related to spas, you can trust us to guide you through it.  – Dave Johnson CEO/Founder