Battling a scum ring around a hot tub is a common problem for many hot tub owners out there. However, it isn’t necessarily a problem that you simply have to live with. In fact, there are many things you can do to clean and prevent the scum ring around a hot tub.

Why does my hot tub have scum lines?

Before we look at how to clean and prevent those rings from forming, let’s first take a look at what those scum rings actually are. Believe it or not, in most cases those scum rings are formed from oils and other chemicals found on our bodies. Common body chemicals that cause this problem are:

  • Makeup
  • Antiperspirant
  • Lotions
  • Oily Skin
  • Aftershave and Perfume

As you can see, these are all very common on all of our skin. When we take a dip in a hot tub, these chemicals wash off our bodies and into the water. Over time, they build up in the hot tub causing the ring to form around the tub.

Of course, it isn’t always our fault. Sometimes it is the water. If our water has an excess of calcium in it, scaling can occur. When this happens, you will begin to notice a scummy coating around the sides and even the fixtures of your hot tub.

Get Rid of That Scum

So, how exactly do you get rid of it once and for all? First, you need to identify the type of scum that you are dealing with in order to properly treat the problem.

1. Test Your Water

First, test your water to see if you have a buildup of excess calcium. If you do, you know that the scum ring is most likely a calcium buildup. Treat your water to reduce the amount of calcium in your spa and then clean the ring with your cleaner and a soft cloth.

2. Remove Those Oils

If your water is fine, then it is most likely a buildup of makeup, lotions and other body oils. In order to remove it, take a soft cloth and add a little of your cleaner to it and gently rub the line until it is gone. Make sure you keep the cloth out of the water, as the cleaner can contaminate the water and even lead to a foamy buildup.

Prevent that Scum Ring from Forming

If you are getting tired of cleaning those scum rings day in and day out, perhaps it’s time to try and stop them before they ever have a chance of forming around your spa. How do you do that? Sometimes, you may get the ring no matter how much effort you put into preventing it. However, there are several things you can do to stop it from forming. At the very least you won’t have to clean off a ring quite as often.

Shower First

Most rings around a hot tub are formed from various oils, makeup, detergents, and antiperspirants found on the body. While you and your friends or family are soaking in the hot tub, the warm, bubbling water slowly washes off some of these chemicals on your body. Over time, these chemicals build up in the hot tub causing that ugly ring to form around the side.

In order to put a stop to the ring, institute a shower first rule before getting into the hot tub. Remove any makeup, lotions, etc. with a quick shower before you go for a soak. While this won’t eliminate every bit of oil and other contaminants found on the human body, it will go a long way toward limiting how much of them can enter your hot tub.

Balance Your Water

Balanced water is happy water, and water that is very clean. You should test your water at least once a week and add the proper chemicals to the water to make sure its pH and total alkalinity levels always remain balanced. If you are battling scum or foam problems, try increasing how often you test and balance your water to see if that helps.

Clean Your Tub Regularly

You should already be cleaning your hot tub on a regular basis, but keeping it clean can be easier said than done, especially if your hot tub gets used heavily. Give your hot tub a good cleaning and regularly clean the filter so it can catch those compounds that lead to scum buildup. In addition to these cleanings, make sure you drain your hot tub once every three months. When you drain your tub, clean and change the filter and give the sides a good cleaning

Shock Your Spa

You should be shocking your hot tub once every 1-2 weeks if you are using your hot tub on a regular basis. Shocking your hot tub with both chlorine and non-chlorine based shocks can help break down the organic materials in your hot tub that lead to scum build up. If you are shocking your hot tub every couple of weeks and you still notice scum buildup, try shocking it once a week. This will give your hot tub an added boost that could prevent that ring from showing on the sides of your spa.


Dealing with scum rings is just a part of being a hot tub owner. Thankfully, they don’t have to be a difficult problem to solve. Using a good cleaner and a few easy to do prevention methods, you can quickly knock out that scum ring once and for all and keep it from ever showing its ugly head again.

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