hot tub without chemicals or chlorine

The word "chemicals" is not synonymous with relaxation or wellness and that is why it makes a lot of hot tub buyers nervous. The key thing to remember is that any chemicals you put into your hot tub water are being added to make or keep the water safe for you and your family to bathe in. You are not adding chlorine to discomfort yourself, you are adding chlorine to make the water safe. You don't add PH balancers to harm your skin, in fact it is probably the complete opposite! So the first key thing to remember here is that "chemicals" are your friend if used safely and correctly. In this article we cover all the questions about using chemicals in your hot tub, natural products, chlorine alternatives and more!

Why do hot tubs need chemicals?

Chemicals are used in hot tubs to balance the water chemistry and preserve the water over long periods (generally up to 4 months). This helps to make the bathing experience better and keeps bathers safe. By not draining between every bathing session, you do not only reduce water waste but also ensure the hot tub stays hot and ready to go!

What happens if you do not use chemicals in your hot tub?

At the very worst, using a hot tub with no chemicals could be extremely dangerous. Certain bacteria and fungi experience optimal growth at temperatures between 25-40°C, which is the exact temperature range of a hot tub! It would take a matter of days for your hot tub water to turn into biological soup, the water would likely turn green and could pose a risk to hot tub users.

Can you use a hot tub without chlorine?

When you wondered if you could use a hot tub with no chemicals, you may have actually been wondering if you could run your hot tub without chlorine. Well then here is the good news, you DO NOT have to use chlorine in your hot tub as there are alternatives to chlorine. Chlorine most certainly gets a bad rep. This wonderful chemical is the most used disinfectant in the world, it keeps our drinking water clean and keeps hot tubs safe. At Happy Hot Tubs, we always recommend chlorine first before looking at other sanitiser options. The reason for this is that it is the cheapest sanitiser on the market, it is the fastest reacting sanitiser meaning it gets to work on bacteria very quickly and most of all, we trust it!

Alternatives to Chlorine


Bromine is from the same 'family' as chlorine however it is slightly slower reacting, slighty softer on your skin and works better at higher temperatures so it has a lot of appeal for many hot tub users. Bromine comes in tablets and is available as infused granules too. Bromine is more expensive than chlorine but it does re-generate when you shock the water unlike chlorine so this in theory allows you to reduce the amount of bromine you need to sanitise the water, which in turn could save money.

One important thing to note with bromine is that it is recommended to perform a chlorine shock on start-up and bromine tablets and granules do contain some chlorine so if you are looking to get away from chlorine completely then bromine may not be the answer.

Aquablanc or O2 Systems

Non-chlorine systems like Aquablanc have become popular on the UK hot tub market. These systems use oxygen tablets alongside an activator liquid to sanitise your hot tub water. They are softer on your skin than traditional sanitisers but they tend to be slower to react, which can cause the water to turn cloudy or green more often.

As with bromine, systems like Aquablanc recommend a chlorine shock on start-up and from time-to-time so this does not get you away from chlorine completely however it will ensure you use very little. 

Other (Natural Hot Tub Chemical Systems)

Over the years the hot tub industry has seen many 'miracle' chemical-free systems appear and disappear. These systems tend to claim they are eco-friendly or natural but usually have one of two key issues. The first is that they can be a cleverly marketed system that contains a normal sanitiser like chlorine but charges a high price, the second issue is that they do not contain a sanitiser at all. The first issue is of course deceptive and unfair but the second issue can be very serious as you could be maintaining a hot tub with no sanitiser, which as we have explained above, can be very dangerous. If you are unsure about a chemical system simply ask the question; 'what is the main sanitiser in the product?', this will help to alleviate concerns and give clarity on what the product is.

Salt Water Hot Tubs

Salt systems are another hot tub sanitising option. Based on technology used in pools for many years, a built in cell uses the sodium chloride (salt) in the water to produce chlorine, which sanitises the water in your hot tub. The Freshwater Salt System from Hot Spring is a great example of a salt system. The main benefit of a salt system is that it is a self-sanitising hot tub and by producing the chlorine naturally through salt it is arguably one of the more eco-friendly sanitising options. It is worth noting that salt systems still require adjustment of your PH/Alkalinity and manual chlorine dosing from time-to-time. Remember a salt system is not chemical or chlorine free, it is simply a way to produce/add chlorine to your hot tub.

Hot Tub Water Conditioners

If you want to add a natural product to your hot tub that will mask the smell of chlorine, helps lock in your PH and leaves you with softer skin after hot tubbing then a great option is Silk Balance. These are dissolvable pods that contain a patented formula of salts. All you do is add one of these weekly to your spa water. Silk Balance works alongside any sanitiser like chlorine or bromine and the benefits offer you a soft, natural feel to your hot tub water. So although you cannot run a hot tub without chemicals, you can run a hot tub without the harsh effects of chemicals. Please note - it is recommended to drain your hot tub and flush out the pipes with Clean Start if you are switching your existing water to Silk Balance for the first time. 

An alternative water conditioner that can help reduce chemical usage and give a softer feel to the water is O-Care. O-Care is a weekly additive that also works alongside your sanitiser to reduce sanitiser usage and give your water a better feel. These water conditioner products are great for people with sensitive skin. 

Is chlorine harmful to bathers?

Chlorine is quite a strong chemical which in turn makes it an excellent sanitiser (killer of bacteria). The use of gloves and eye protection is recommended when handling the chemical in its raw form. When added to water chlorine is much less concentrated and if your free chlorine levels are kept between 3-5ppm, it will not be harmful to bathers. 

What hot tub chemicals do I need?

Our Happy Hot Tubs Chlorine Starter Kit or Bromine Starter Kit contains everything you need to get going and you can check our Beginners User Guide for more specific hot tub chemical balance information.

Can hot tub chemicals cause a rash?

In most cases a rash from a hot tub is actually caused by a lack of chemicals! In a situation where the hot tub water is not properly balanced, bacteria can form which can cause skin issues such as a rash. Balancing your PH is also a really key factor in making sure you do not get skin irritation. If you experience a skin reaction in a hot tub, please consult your doctor.