I've had some issues balancing my pool and realized I needed to SLAM because I have 0.4 free chlorine and 4.0 combined chlorine. I have a SWG but my CYA is around 40 after the initial pool opening. I kept my CYA at 40 for the slam even though the SWG pools should be between 60-80. Pool math told me to SLAM at FC 16 so I started few days ago. Initial FC was 18.2, little high, but came down to 9.2 next day so added more chlorine. Thought I had the calculations correct but free chlorine shot up to 26 and came down to 22 this AM. Water is clear with a CC of 0.4.
So I have a few questions.
1.How accurate is the Taylor FAS-DPD at high chlorine levels? The titrating fluid seemed to take on a light orange color after 100 drops of 0871.
2.Does the Taylor FAS-DPD test at 10ml have the same accuracy as at 25ml. I tested both ways and got really different numbers.
3.When doing the OCLT, is it any any FC level or just when the FC is below the SLAM level. For example, my FC started at 26 (well above the 16 slam value) and came to 22. Should I wait until FC is around 16 before I repeat the OCLT?
Thanks for any suggestions