These are great if you need to test your water for alkalinity, free chlorine, pH, total hardness, total chlorine, cyanuric acid, nitrite, nitrate, and bromine. Its very easy to use. You dip a test strip into the water and put it down flat and wait 30 seconds. Then you compare it with a chart. I did have some trouble with a few because the colors did not match up so greatly, but I was able to figure out a closeness to some. You can use these to test your water from your faucet, pool, spas, or anything that needs it. I tested my tap water versus bottled water and I was smart to stick to bottled water over my tap water. You get 100 strips to use so this will last you a while.
You can purchase them on Amazon at this link; http://amzn.to/2dnqwy0
If you would like to see my video review please see my Youtube; https://youtu.be/a4woeln0Ge4
Disclaimer: I received this product free from the seller for my complete and 100% honest and unbiased review. I only give my honest review on a product.