Open Your Pool: Testing The Water

We’ve spent the last few days giving you the proper steps to begin to open your swimming pool for the spring. We touched on chemical safety and the basics of water testing, but now we are going to go into a bit more detail on how to get your water perfect for that first swim of the season.

You will want to circulate your pool water for 24-48 hours before testing it. You can either test it yourself, or bring a sample to your local pool retailer. Make sure that when you collect the water, you do so in a clean, plastic container. When you scoop a water sample, go at least elbow deep in the water for the best results. After this initial testing, you should re-test at least once a month during the pool season.

Pool Water Optimum Levels:

  • Chlorine: 1.0 – 3.0 ppm

  • Bromine: 1.0 – 3.0 ppm

  • pH: 7.2 – 7.6

The water's pH is a measure of its total acid-alkalinity balance -- the relative proportion of acids and alkalis in the water. Simply put, water that is either too acidic or too alkaline will cause undesirable chemical reactions.

Total Alkalinity:

Range: 125 – 150 ppm 

This measurement refers to the alkaline materials dissolved in the pool water.

Calcium Hardness: 

Range: 200 – 275 ppm (plaster pools)
             175 – 225 ppm (all other)

This is the amount of dissolved minerals in your water. If the level is low, your equipment can erode. If it is high, your water can be cloudy.

LSI (Langelier Saturation Index):

Range: -0.5 - +0.5 

This measurement is a way to evaluate your water quality data to determine if your pool has the tendency to form scale.


Range: 0 ppm

Fill or ground water can cause copper, iron, and manganese can find their way into the pool. The copper and iron can also be caused by metal accessories like the pump corroding.

If you are having a problem getting your pool’s water to the correct levels, seek the advice of a pool professional or check out the Pool Care Troubleshooting Guide on