EHM pH Test Liquid

I purchased this product to test the alkalinity of the EHM sureflow alkaline filter, which I also bought on the EHM website. 1. This Ph solution is very affordable. 2. The instructions are simple and straightforward. 3. Using it was easy. 4. The only draw back I have encountered is determining the alkalinity level base on the color changes during the test. This can be a bit challenging as my eyes are getting older, making it harder to distinguish subtle color variations. Overall, this is a simple to use and affordable product.