Industrial Test SystemsWaterWorks 480023 Free Chlorine Test Strip, 5 Second Test Time, 0-25ppm Range (Pack of 50)

So simple to use and results are quick. I have a cheap filter system which is supposed to remove residual chlorine from our city water. I have been using the filtered water to wash my face, as I understand chlorine is readily absorbed into the skin. I was curious to know if it really worked. The city water showed a small amount of chlorine (the palest blue) and the filtered water showed no indication of chlorine at all. This gives me confidence my filter is doing as promised and this was a simple and cheap way to find out.

I tested this with water out of the faucet (which I know is high in chorine as we have high levels of TTHM's and HAA5 and with treated water from my Berkey. All were the same, showed 0 chorine so the test is either defective or does not work.

Works well for me! Affordable way to check on filtration. I have used these with unfiltered water to check accuracy and I feel confident these strips work. I would recommend to others!

It works fine, but it is no better than the much lower cost strips

Works as needed. The colors are a bit hard to decipher. The biggest problem I have, is sometimes you find 2-3 strips that are cut in half length wise so they are unusable. Overall, pretty decent for what I'm using them for.

I use these strips monthly to check the water/filtration system in my and my Aunt’s home. Easy to use and match to chart. Can’t beat the price at less than $.50 per test. Strips last well over a year.

I cross referenced the results with other testing methods and found these to be accurate. Great quick test.

Not accurate. I compared this test system several times over several days to a liquid test kit and another dip strip both of which indicated 3 times more free chlorine.