Overstabilized Pool Water

What is stabilizer?

Outdoor chlorinated pools require stabilizer (cyanuric acid) to protect the chlorine from being burnt off by UV rays from the sun. The ideal level of stabilizer is between 30 and 70 ppm for Chlorine based pool and between 50 – 70 ppm for Salt water pools.

How does stabilizer get into my pool?

Stabilizer can be added in a pure form as a granular (Pool Stabilizer) or as a liquid (Instant Conditioner). Stabilizer is also mixed into stabilized pucks as well as stabilized chlorine.

When is my pool overstabilized?

A pool with a stabilizer level of over 70 ppm runs the potential of being overstabilized. Too much stabilizer can begin to lock the chlorine in your pool (chlorine lock) and render it useless. There is no exact level of stabilizer that guarantees chlorine lock. You can determine if a pool is overstabilized by testing its stabilizer levels and seeing if any problems are occurring. Chlorine lock symptoms are the same signs as a pool with no chlorine, such as cloudy and/or green water, and/or a strong chlorine smell.

How do I lower stabilizer?

The only practical method of lowering the stabilizer level in a pool is by dilution. There are no products available that lower stabilizer. We recommend not draining more than 1/3 of your pool at a time.

For Example: a 16 x 32 pool with 72,000 L of water in it has a 100 ppm stabilizer level. The average depth of the pool is 5 feet (3 foot shallow end and 8 ft deep end). The homeowner drains 1 ½ feet of water from the pool, and refills the pool with fresh water. This will lower the stabilizer level by 1/3. Now, the pool has 66 ppm of stabilizer and is within the optimal range for effectiveness.