Hot tub scum is a common occurrence for tub owners, and can be pretty off putting if you’re wanting to dip and soak. Here’s everything you need to know so that you can enjoy your tub with it sparkling in the sun, or under the stars.

What is hot tub scum?

Hot tub scum is a ring that gathers around the top of the water. It sticks to the sides of your hot tub and can look pretty unsightly, but for the large part it isn’t anything too sinister! However, we know that you want your tub to look inviting, so here is a bit more about hot tub scum and how you can get rid of it.

What causes hot tub scum?

It is caused by a variety of things, and here are the most common ones. 

Chemical residue 

An imbalance in your chemicals can cause hot tub scum to form, leaving a residue round the side of your tub. The most common thing is the pH balance being too high, which is easily done when you’re topping up your hot tub chemicals.

Lotions and potions 

Things like moisturisers and perfumes leave behind particles that gather and form a type of hot tub scum. This is one of the more inevitable causes, as it is highly likely that you will have some form of product on your skin before getting into the tub. 

Metals in the water 

If you have metals in your water supply, which many of us do, then these can come away in the tub and gather together oxidising with the chlorine, leaving that greyish ring around the top of the water.

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Old filter

If your filter is dirty or has seen better days, it might not be working as hard as it should be to prevent against hot tub scum! Clean your filter and replace it if you need to in order to keep the water crystal clear and scum-free.

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Ah, humans.

We lose up to 100 hairs a day from our head, and we shed up to 5 billion skin cells a day, too. Without going into too much detail, they have to go somewhere, right? We can group all of these things together as human-caused, meaning if you spend time in your tub, which we hope you do, you likely have hairs and skin cells in the tub with you. Now, don’t be too grossed out as it is perfectly natural, but it does mean it can be a cause of crum build up in your hot tub!

How can I get rid of hot tub scum?

Hot tub scum is not something you want in your line of sight while you’re trying to enjoy some time to yourself or with loved ones, so here are the easiest ways to get rid of hot tub scum, and even prevent hot tub scum, too.

Scum absorbers 

You can buy specialist scum absorbers that will help you get rid of it in your tub. These are usually reusable and they trap hair, oils, and other scum-causing substances so that you can enjoy your tub without the ring. They’re a good choice because they sit in your tub and gather the debris without you having to do too much of the hard work. If you have a larger tub or scum build up seems to be a semi-regular issue for you, they’re a good option, and keep the tub fresh. 

Wipe it down 

You can wipe the scum away with a damp cloth. It is a good idea to drop the water down slightly below the ring for easy cleaning, and you can refill it once it is spick and span. Wiping away the scum is good for bits of build up but not a total ring around the water. It’s a quick and easy fix that is minimal effort for maximum impact. 

Regular filter cleaning 

Maintaining your filter cleaning and changing it out when you need to is one of the more effective ways to manage and prevent hot tub scum. This is because the filter does all of the hard work in keeping the water clean and the nasties out. Remember to separate the grooves in the filter when you’re cleaning it to remove anything that might still be lurking, and you will need to check your filter for cracks and deformations, so you can be sure it can get to work properly. 

Regular water changes 

Changing the hot tub water every three to four months is another great solution. When you drain your tub, properly cleaning it before refilling it makes sure that there is nothing left lurking before you add fresh water. Hot tub scum can be caused by old or dirty water, so make sure that you are refreshing the water regularly and taking the time to clean the tub as you should as part of your maintenance schedule. 

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Clean people, clean tub 

Shower before getting in the hot tub to minimise build up from skin and hair products, as well as skin and hair themselves! While it is not always realistic, it can go a great way to helping with the build up of scum. Products are one of the biggest culprits, and things like moisturiser and sunscreen are particularly notorious for causing scum build up. In the summer, you may need to keep an eye on the scum rings with added use of sunscreen and other products. 

Water checks 

Make sure you’re checking the water balances and chemicals within it so that you can not only enjoy your tub but prevent the pH from impacting the scum lines in your tub, too. This is another common issue and while there will always be discrepancies in the water and chemical levels, if it is a regular occurrence, the scum can be tricky to manage.

How can I prevent hot tub scum?

The only way you can prevent hot tub scum is to work through those steps above we mentioned, and even then there is no guarantee that you will not get hot tub scum in your tub. It is a very common occurrence in tubs, and as long as you clean it as soon as you notice it, there shouldn’t be any problems or lasting marks on the walls of your tub. 

Avoid doing these things

It can be tempting to get the bleach out or the regular cleaning products which can be harsh on the hot tub walls and even damaging to them. Avoid using any cleaning products that are not made for hot tubs, and do not try DIY methods like nail varnish remover as solutions like this can damage and even melt away certain materials. Make sure you are only using specialist cleaning products, and maintaining your tub.