Hach Free & Total Chlorine Test Strips

Recently I purchased a whole-house water filter to remove chlorine from my shower and bath water. This filter was a "compact" type for under $300 and because of its size needs to be replaced every year or so, similar to a refrigerator filter.

To determine when my carbon filter was expired I wanted to buy chlorine test strips because they are inexpensive, quick, and easy to use. I've been happy with the Hach Free & Total Chlorine test strips and decided to write up a quick review.

Free and total chlorine

The Hach test strips are a visual indicator measuring six different levels of free and total chlorine: 0, 0.5, 1, 2, 4, and 10 parts per million (ppm). Because these strips measure free chlorine they can also be used for testing swimming water.

  • Free chlorine – This is the chlorine you typically test for in your pool water. It's a measure of chlorine that is still available to sanitize your pool, as opposed to "combined" chlorine which has been used up in the sanitation process.
  • Total chlorine – The sum of combined and free chlorine. If the total chlorine in your water is higher than free chlorine, the difference is represented by combined chlorine. If the readings are the same, then no combined chlorine is present.

Test strip accuracy

My local water department publishes a report each year about our chlorine levels and I could see that my tap water had around 1 ppm. Therefore, I wanted to buy a test strip that was sensitive enough to measure below that level.

To use this product you simply dip the end of the test strip in your water and wave it back and forth for 30 seconds. The color of the strip will change depending on the presence of chlorine. Then you compare the color to the reference ranges on the bottle.

After I had my whole-house water filters installed I was able to test their effectiveness. First, I turned off my water filters (bypassed them) and when I tested my tap water it was exactly at 1 ppm as my local water reports stated. Then, after I engaged the water filters again the chlorine fell to zero.

This isn't a sophisticated test of the product but it indicates to me that these strips are roughly in line with my local water data. I consider them good enough to determine when my water filters stop working and need replacement.