The Pool – Total Alkalinity

Stabilised Chlorine vs Unstabilised Chlorine

The SpaChem team often gets asked what the difference is between these two recommended forms of chlorine and which one should be used. So, we have popped together the following to help you make the decision….let’s get started!

You have been through the pro’s and con’s of using bromine vs chlorine and you have chosen chlorine as your hot tub or spa sanitiser. The next step is to work out which form of chlorine will work best for you. Do you opt for stabilised chlorine granules or the multi-functional chlorine tablets?

My multifunctional chlorine tablets say they contain unstabilised chlorine. What is unstabilised chlorine?

Unstabilised chlorine is chlorine without the addition of cyanuric acid. Cyanuric acid stabilised chlorine which in effect makes it last much longer when you use it within your spa or hot tub. Many multifunctional chlorine tablets contain the unstabilised form of chlorine, so it’s worth reading on to find out how they impact the water management of your hot tub (remembering that they do have many other additional benefits).

The unstabilised form of chlorine dissipates more quickly, and as a result, you will have to add more chlorine to ensure that you maintain the sanitisation of your water. This is especially the case in the summer months as the UV rays from the sun make the chlorine ‘burn off’ quicker.

However, if your pool, hot tub or spa are undercover, then unstabilised chlorine could be the best form for you as it won’t get affected by the UV rays. If you are going to opt for this form of chlorine, then it’s worth remembering that due to the lack of stabiliser (cyanuric acid) it won’t stay in water for long. Daily testing of your water is essential, remembering to add chlorine when required to maintain the optimal 3ppm.

What is stabilised chlorine?

Yep, you’ve got it… stabilised chlorine does contain cyanuric acid which in effect makes the

chlorine stays in your water for longer and more efficiently as you won’t have to add as much (or as frequently) as unstabilised chlorine.

Stabilised chlorine is often in the form of granules which are much quicker to dissolve than their multi-functional unstabilised tablet counterparts resulting in a speedier response to your change in chlorine level readings. Which is another reason why chlorine granules are great to use when you need to shock your hot tub water.

Stabilised chlorine does however come with a word of warning in that if your cyanuric acid levels (the stabiliser) get too high, this will have a negative effect on the chlorine itself. If this is the case, then our recommendation would be to undertake a partial drain-down to allow you to dilute the concentration and rebalance your water chemistry.

Should I use stabilised or unstabilised chlorine in my hot tub/pool?

We are not ones to sit on the fence here at SpaChem, as we like to be able to give you our expert recommendations, but in answer to this particular question, there is no right or wrong. It is however more a matter of understanding what hot tub, spa or pool you have, where it is located, how to use each form and not forgetting your own preferences.

Many of our customers prefer not to choose between the two forms of chlorine and decide that to achieve the perfect water balance they like to use a combination of multi-functional chlorine tablets and chlorine granules – and we quite like this approach!

Hassle-free multi-functional tablets used in a dispenser are great for the day-to-day maintenance of your chlorine levels. Which when used in combination with stabilised chlorine granules for shock-dosing and immediate changes to your chlorine levels results in the perfect water chemistry.

Order Your Hot Tub Treatment From SpaChem

To find out which form of chlorine will work best for you, have a go using both and combined with your daily testing, you will soon work out your perfect solution. We offer the best hot tub chemicals online. If you would like to talk to one of our water management experts about all things chlorine related, give us a call on: 02920 280422 or WhatsApp on: 07540 184405.