Turn on pump to verify circulation and run for at least 15 min before testing. When you get your tests results post in this format:
FC:
CC:
PH:
TA:
CH:
CYA:
That makes it easy to read. I suspect your CYA may be pretty close to zero. You will want that to be at least 30 or you will loose a lot of chlorine (which translates money) to the sun. Also, may want to adjust ph before Slam. I have a liner pool so I do not mess with TA or CH before a SLAM but since you have plaster you might want to read about that or get advice from someone who knows more about plaster. Asking questions beats making mistakes. Best of luck tomorrow.
FC:
CC:
PH:
TA:
CH:
CYA:
That makes it easy to read. I suspect your CYA may be pretty close to zero. You will want that to be at least 30 or you will loose a lot of chlorine (which translates money) to the sun. Also, may want to adjust ph before Slam. I have a liner pool so I do not mess with TA or CH before a SLAM but since you have plaster you might want to read about that or get advice from someone who knows more about plaster. Asking questions beats making mistakes. Best of luck tomorrow.