JavaScript seems to be disabled in your browser. For the best experience on our site, be sure to turn on Javascript in your browser.
Customer Service: [email protected]
What is Chlorine Lock in a Pool & How to Break It
Swimming pool owners may have come across the term ‘chlorine lock’ before, and while some disregard it as a myth, the reality is that many users have experienced problems when using chlorine.
Here, we take a look at what chlorine lock is and what you can do to ensure that your pool is properly sanitised and safe to enjoy! And, if you're still unsure about how to use chlorine, you can head over to our guide to chlorine tablets versus granules.
Essentially, a chlorine lock means that the chlorine in your pool is not working as it should to sanitise the water.
This issue is brought about by the presence of too much cyanuric acid, which can overpower the free chlorine in your pool.
Cyanuric acid (CYA), also known as stabiliser, is used to protect the unstabilised chlorine in your water. Without it, chlorine can be broken down by UV rays from the sun, rendering it ineffective. However, too much CYA can also make the chlorine in your water useless; chlorine lock is what happens when the right balance is not struck.
Potential signs of chlorine lock include:
This smell is produced by chloramines in your pool which signifies a build-up in improperly-treated pool water.
If you test the chlorine levels in your pool and the total chlorine levels and the free chlorine levels are unequal, you may have chlorine lock. Under normal circumstances, these two numbers should be the same.
Chlorine is an essential part of your pool’s chemistry, so it is important to rectify a potential chlorine lock.
Before trying any solutions, you should test your water first to identify whether the problem is definitely chlorine lock; you don’t want to disrupt your pool chemistry so extensively that a full pool drain is required.
A partial drain where you drain a portion of the water and replace it with fresh water can often be the best option.
Draining a quarter of your pool water, refilling it and then testing the chlorine levels is something that may be beneficial. If the chlorine levels have not come back to an appropriate number, you can drain more water and retest. This will give you more control over how much water you refill and will ensure you reduce waste.
Another effective solution can be a non-chlorine shock treatment. You must be careful about how much shock you add.
Chlorine shocks can be used to help your water reach breakpoint chlorination. This is when the residual chlorine drops rapidly thanks to the break-up of the chemical bonds that make up chloramines.
Before attempting this method, you should make sure that your water’s pH level is between 7.2 and 7.6.
For more guidance on how to fix common pool issues, check out our blog which is full of helpful tips and tricks!
