Slamming

[ksepurvis]

This is my third year with TFPC, and I no longer buy any pool chemicals! This year promises to the be very best balanced, most beautiful pool ever! I have one question about my SLAM though.
Prior to SLAM:
CYA (after emptying pool 75%): An amazing 55!!!!!!!!!!!!!!!!!!!!!!!!!!!!! (I will NEVER use pucks again!)
PH 7.5
TA 90
FC 7
(We SLAMMED after draining for CYA and refilling).

SLAMMED to 23 (FC 7/CYA 55 =SLAM 23)
Last Night FC 23
This Morning FC 21 (Drop of 2 ppm)
No CC's
Water crystal clear


My question: We had a TERRIBLE storm last night that dumped a lot of leaves, pollens, sticks in the pool. We got most of it out, but then it hit again overnight and dumped on us again. With that in mind, would an FC drop of 2 be acceptable? If not, do I need to get FC up over, say 25-26 to be sure?

 

[Mr Bruce]

If the water is clear, holds FC overnight (OCLT) and your CC is <= 0.5 you don't need to SLAM.

 

[tim5055]

Before I did a SLAM I would do an Overnight FC Loss Test (OCLT) to verify. Clean it out, including skimmers and bring the FC up to 10 as the sun sets toninght. Test & re-test in the morning. That difference will tell if you need to SLAM.

If you do have to SLAM your target is 24 with 60 as your CYA.

 

[mytmouse]

I had an 8 day slam recently with 50 CYA... i had a few nights with a -2 or -3 OCLT. I just couldn't get to -1 or less, as it would go from 20 to 18 or 17. clear of course and <.5 in all cases, just above 1 OCLT....When i FINALLY used TWO heaping/good size spoonfuls of reagent instead of 1, my tests seemed to be a little more accurate. That was an additional note in the instructions that i must have missed or ignored (use more with higher PPM). Now that I am back down to 4-6, i still use one heaping.