Before I joined this forum I ordered a drip test kit from Amazon Poolmaster 22270. It seems to have really good reviews and the results are pretty easy to read. However, I have 3 different dip kits and results from tests at Pools Plus that all seem to disagree with each other when testing PH and FC. Can anyone explain why I am seeing such a big difference?
Poolmaster Kit Dip Strips Pools Plus
PH 7.2 around 7.2 7.6
FC 2 ppm around 5 ppm 6 ppm
CYA around 30 (dip test)
Which ones should I trust and why the big difference?