Hello from NC. I have a 25000 gal inground vinyl pool. I have used the FROG system since we installed our pool 3 years ago. I am tired of the high price tags at the pool store and want to be able to test and know how to treat my own water. I bought the TF100 test kit and did my first tests tonight. Looking forward to learning from everyone on this site. My kids are begging me to let them swim since school is closed, but I want to get everything set before I turn on the heater and let them jump in. I am actually ready for pool season myself. I think time in the sun will be a welcome relief from all the mess going on right now.