Good morning. We have a 40,000 gallon saltwater fiberglass pool. I saw this site recommended on a Facebook group. I’m looking for the best way to test our water. It’s clear, but sometimes I “feel” it is not right even though the strips we’ve been using show it is ok. I feel like there is a film when I get out of the pool. I also welcome all general advice. This is our second summer with the pool. Thank you.