How to maintain your hot tub

How to maintain your hot tub

We know here at Outdoor Living know that a hot tub is a significant investment, so why wouldn't you arm yourself with all the information necessary to take care of your tub. This beginner's guide will help you through your first steps in spa ownership and ensure you have all the knowledge needed to set up your hot tub or spa.

Let's start with the basics

All hot tubs require regular maintenance to keep the water healthy and safe for bathers. Before getting started you will need to choose what type of chemicals to add based on your needs and skin sensitivity. Our chemical essentials can help you choose the right sanitiser.

Setting up your shiny new hot tub

When a hot tub is filled with fresh water, it is important to add a sufficiently high dose of sanitiser. This can be done by adding 60g of chlorine granules per 1,500 litres of water to start the sanitation process and allowing the level to drop to 3-5mg/l (mg per litre) before using your spa.

To dose your hot tub ready for use, we advise using chlorine or bromine granules. Then, ensure your spa water is at a normal level of 3-5 parts per million (ppm) for free chlorine and 4-6 ppm for bromine before taking a dip.

Don't forget about filters

Most acrylic spas will have a cartridge filter system and hot tub pump. You should regularly check that your filtration system is in good working order at least once a week. Please note that when your hot tub cartridge filter is dirty, its performance will deteriorate. This can lead to dirty and potentially contaminated water.

Usually, spa cartridges will need cleaning weekly (depending on use), however, we would advise more regular cleaning if your hot tub is being used a lot. Other factors that can affect how often you should clean your filters are contaminants like grass, leaves, fake tanning products, body creams, make up, soaps and detergents.

How to test hot tub water

Testing your hot tub's water is a vital step to keeping it clean, safe and healthy. For quick and accurate detection, we recommend using test strips to check the sanitiser, pH and total alkalinity levels of your water, this then allows you to make any chemical adjustments that may be required. We recommend testing your water daily whether the spa is in use or not.

When using test strips, please follow the instructions carefully. After testing your water for several months, you’ll learn how refilling, topping up, adding chemicals, and general usage affect your readings and chemical levels.

Hot tub water care and spa maintenance

Sanitising your water

The 2 most popular hot tub sanitisers are chlorine and bromine. We highly recommend using granules to maintain your spa, these should have a reading of 3-5ppm for free chlorine and 4-6ppm for bromine.

It is important to note that the rate of chlorine/bromine consumption will vary depending on the usage of your tub. The consumption of chlorine / bromine will continue even when your spa is not in use. Therefore, we recommend testing your hot tub water daily.

Check out our chlorine of bromine maintenance guides for more information.

Balancing your hot tub’s water

Balancing your hot tub water is a vital part of being a good hot tub owner. The pH scale measures acidic and alkali conditions using a guide of 0-14. pH 7 is neutral, meaning anything below 7 is acidic, while a pH rating of above 7 gives you an alkaline reading.

The ideal pH level for bromine is 7.0-7.4, and for chlorine, the ideal pH level is between 7.2 and 7.6. This is to ensure your spa equipment is protected and any friends and family who come to bathe can do so in comfort. If your pH level is incorrect, you will need to use more chlorine or bromine, as your chemicals won't be as effective if your pH levels are not correct.

So, let’s talk about Total Alkalinity and Total Hardness

Maintaining a balance between Total Alkalinity (TA) and Total Hardness (TH) of the water is essential. Low levels of alkalinity can cause scale within a hot tub. You can raise the alkalinity with Alkalinity increaser and lower the alkalinity by pre-dissolving pH minus in a water bucket and pouring it directly into the centre or deepest part of your hot tub with no jets running.

However, high pH levels due to hard water can be prevented with regular doses of No scale. Please note this product does not reduce the level of hardness in the water, it prevents the build-up of scaling so hot tub elements are not damaged by the hardness.

Hot tub foam – what to do if it appears

If foam is appearing on the surface of your water, it is usually caused by remnants of detergents left in bathing costumes. It is always a good idea to encourage hot tub bathers to shower with their costumes on before using your hot tub. This will not only help to remove detergents but will also remove cosmetics and lotions.

If foam does occur then there is a simple solution, Antifoam.

General cleaning

Periodic cleaning of waterline grease using surface cleaner , will not only keep your spa looking fresh, but it will also optimise the use of any spa chemicals dosed into your water.

Note: It is vital to use specific spa cleaning chemicals as many household products contain chemicals that can cause foaming in a hot tub or alter the pH.

Draining your hot tub

Over time your spa water will absorb minerals, chemicals, and other soluble materials, which will lead to an increase in Total Dissolved Solids (TDS). TDS reduces the efficiency of spa chemicals, making the water harder to maintain.

With the above in mind, The British and Irish Spa and Hot Tub Association (BISHTA) advises that the change of water should ideally be done once every month, but it may be extended up to once every 3 to 4 months if tub usage is low. When doing so, it is a good idea to clean your hot tub pipework using pipe cleaner to maintain clear, working pipes.


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