Pool Chlorine Level NOT Registering after Shock

Is your pool chlorine level NOT registering after shock? If your free chlorine levels PPM (Parts Per Million), are not rising with your test strips after extensive shocking, you’re not alone. This is a common problem that many pool owners face at some point in time. Usually early on in ownership.

You would not believe how many new pool owners think that they simply need to shock and vacuum a pool to keep it maintained throughout the season (I used to be one of them). In reality there are many other factors that come into play to help you maintain clean, safe, and sparkly water.

For example, if your chlorine level is not registering on your test strips after multiple shock attempts, the reason is most likely that your pool needs a conditioner or stabilizer that contains Cyanuric Acid. Without this conditioner or stabilizer, water will lose chlorine very quickly to the sun. A pool with no cyanuric acid can lose all of its chlorine within just two hours. Cyanuric Acid works much like Sunblock does to protect our skin from damaging UV rays. However, in the case of a pool, this stabilizer keeps the UV rays from breaking down the chlorine.

Raising a Low Pool Chlorine Level

The following steps should be performed when a pool has been shocked but the chlorine level never rises. Or when the chlorine level doesn’t remain stable for more than a couple of days.

  1. First, you will need to test your cyanuric acid level.
  2. Next, add a pool conditioner until reaching the ideal range (30-50PPM).
  3. Then, test your chlorine level after the cyanuric acid has been dispensed and is well circulated. You will likely notice chlorine suddenly registering on the test strip. In fact, the chlorine level might even register a bit high, and you won’t need to add any more.
  4. Finally, continue to test your cyanuric acid level once a month throughout the season to keep the PH level balanced.

Note: If you are using dichlor or trichlor as your primary chlorine sanitizer, you are already introducing cyanuric acid along with the chlorine and may be experiencing another problem.