What Hot Tub Chemicals Do I Need?

When you’re dreaming about buying a hot tub for your home or garden, then you’re probably imagining how relaxing it will be to jump into the bubbling, hot, soothing water after a long, stressful day.

And while that’s one of the many hot tub benefits, there’s also the less glamorous side of hot tub living to think about – that is, making sure that your hot tub water is chemically balanced.

So, whether you’ve just bought a hot tub or you’re thinking about buying one, here’s what you need to know about hot tub chemicals.

Why You Need Hot Tub Chemicals

Most people think of hot tubs like baths when really, they’re more like swimming pools. Hot tubs are designed to recirculate the same water for weeks or months at a time, which you’ll be glad of when it’s time for your quarterly drain, clean, and refill.

Because you’re not changing your water frequently, and it’s at a cosy temperature, it’s the perfect breeding ground for nasties like bacteria, fungi, and algae.

Over time, these build up in your hot tub’s lines and on the filter, meaning that your system has to work harder to pump water through. And the water that circulates will likely look cloudy, off-color, or smell foul.

Not only that, but these contaminants can cause all manner of health issues from skin infections to Legionnaire’s Disease. Which is the exact opposite of what you want a hot tub for.

Thankfully, keeping the chemicals in your hot tub balanced, as well as implementing a regular cleaning routine, can keep these nasties at bay and leave you with a clean, relaxing hot tub.

The Hot Tub Chemicals You Need to Buy

Let’s take a look at the necessary hot tub chemicals you’ll need in your hot tub toolkit.


This is one of the most important chemicals to keep stocked up on. While you’ve probably already heard of chlorine as a sanitizer, there are a variety of different sanitizers available.

As always, we recommend checking your manufacturer’s guide to see what sanitizing chemicals they recommend, as some hot tubs are set up to work with specific hot tub chemicals.

Commonly used sanitizers include:

  • Chlorine
  • Bromide
  • Minerals
  • Salt (only when used with a salt system)
  • Biguanide


Maintaining a good alkaline balance stops the pH of your water from changing too drastically, but getting the balance right can be a delicate task. The proper alkaline level for your water is between 100-150 ppm, which again, will depend on the manufacturer’s recommendation and the other hot tub chemicals you’re using.

So, you’ll need to keep an alkalinity increaser in your cabinet for if the alkaline levels in your water drop below 100ppm. And, if the alkaline level is too high, you’ll need to use a pH decreaser.


When your alkaline levels are balanced, you’ll need to use pH increaser and decreaser to maintain the water pH between 7.4 and 7.6. If it’s too high or low, this can damage your hot tub’s internal systems, not to mention make the water cloudy or uncomfortable.

Like alkalinity, this is a delicate balance. pH increaser will also increase the alkalinity and the reverse for pH decreaser. When you’re adjusting these levels, particularly if it’s your first time, you’ll need to be patient and continuously test until it’s balanced.


You need the water in your hot tub to have a degree of calcium hardness to protect the internal systems. However, it can’t be too high, otherwise it’ll cause scaling around the waterline, jets, and internal components.

You’ll need to keep calcium harness increaser for this reason, but we recommend only adding a little at a time until you reach the required levels of between 175-250ppm.


Shock is a quick sanitizing chemical that can clear up problems like algae blooms or cloudy water, and we recommend you always have this on hand.

Regular hot tub users should be using this at least weekly. The shock you need will depend on the sanitiser you use, but it comes in both chlorinated and non-chlorinated options.

Optional Hot Tub Chemicals

These chemicals aren’t necessary and you can maintain a clean and sanitary hot tub without them, but they offer some additional benefits.

Water Clarifier

If you wake up to find a cloudy hot tub but you haven’t got time to get to the root cause, water clarifier is a temporary remedy to make the water more inviting.

Emphasis is on the word temporary, here, because it will wear off.


These enzymes will break down organic contaminants that enter your hot tub water, which can help to keep your water cleaner for longer.

If you maintain a regular cleaning cycle and keep your water chemically balanced then they’re not always necessary, but they’re nice to have if you like a squeaky-clean hot tub.


Your hot tub water could foam if it’s contaminated with soaps and detergents, or if you didn’t rinse down your hot tub well enough the last time you cleaned it.

If your water’s foaming and you don’t have time to test your water or clean your hot tub, then a defoamer is a good temporary option to fix your water condition.

Shop Hot Tub Chemicals at Euphoria Lifestyle

Keeping your hot tub water chemically balanced is the key to maintaining a clean, sanitary, and relaxing hot tub.

At Euphoria Lifestyle, our hot tub experts can walk you through how to introduce and balance the chemicals in your hot tub, as well as recommend you professional products, such as chemicals and accessories, to keep your spa sanitary.

Tried to balance your water but it’s not working? Need an expert to show you how it’s done? Our expert hot tub technicians are on hand to help you.

Simply get in touch with us to request a service, and we’ll be happy to show you how best to keep the chemicals in your water balanced.

Whether you’re looking around for the best hot tub prices or hot tubs for sale in West Sussex, Euphoria Lifestyle has you covered.

Did you know that we also have a blog and online learning hub? Here, you can find a range of articles about hot tubs and garden leisure. To get started, take a look at this blog about using your hot tub more often while working from home!