Ever since the pool was opened this year (week ago), the water has been a light green color, mostly in the deep end. I had a pool maintenance guy come over and do the necessary things to get it up and running. However, it seems to be lacking Free Chlorine (FC). I'm unsure of what to do next, as all of the other levels are in normal range. He put 4 Chlorine tablets in, shocked it and cleaned everything, still no dice.
Total Chlorine: 3
Free Chlorine: 0
Using an AquaCheck Select test kit.
Appreciate the help!