First SLAM

[robdac]

For the last week I haven't been able to keep much FC in my pool. I keep turning the SWG up (from 20 to now over 60%) and every morning when I test the FC it comes in at 1-2 FC. I want it at 5+ based on my CYA. The water has been clear throughout with no CC. Still, I suspected an algae growth. CYA is at 80. I decided to SLAM to be on the safe side.

Yesterday I added at ton liquid chlorine to bring the FC up to a calculated 31 (pool math, no test) in the morning and left the SWG running. After dusk I tested the pool at 25 FC and made sure the SWG was off for the night. This morning at dawn I measured 22.5 FC, still with no CC's. I added more liquid chlorine to bring it back up to 32 FC this morning and fired up the SWG to maintain for the day. The water is crystal clear. There are no CCs. But, the OCLT dropped by 2.5 last night. I assume this means I need to keep going on the SLAM since the drop was greater than 1.0.

Question: At high FC levels (like 30) is a drop of more than 1.0 appropriate on the OCLT? Thanks.

 

[Smykowski]

Yes, keep SLAMing. The 1.0 drop is what allows for testing error and oxidation of the cover, etc. Any more than 1, and there's something still in the pool.

 

[robdac]

Thanks!

 

[robdac]

Still haven't passed the OCLT. Last night it was at 26.5 and this morning it was 25.0. So, I'm almost there. Brought it back up to calculated shock lever for 80 CYA (31) and we'll test again tonight. Looks like I'm getting very close. Still no CC's and the water is crystal clear.

As an aside, I'll never run the CYA up to 80 again, even with a SWCG. It takes way too much chlorine if you ever need to do a SLAM.