Leave SWCG Generating During Slam?

revitup

Bronze Supporter
Nov 30, 2019
315
Pawleys Island, SC
Although my pool is clear with no visible algae, I noticed the stairs seemed a little slippery. I did an OCLT and of course I lost 2.0 ppm FC overnight. I never let FC get below 5 ppm with CYA of 60-70 so how algae could have formedI have no idea. That's not the question though.
Given that the SWCG has had no problem holding a steady FC level of 5-7 ppm (I test most every day), does it make sense to just let it continue to generate FC at my normal output while slamming to help hold the required slam FC level?
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
With slippery steps and a failed OCLT, I'd go right into the SLAM Process. The sooner the better and hopefully will make for a quick SLAM. But be thorough and don't skip any steps. Brush everything well and use liquid chlorine or regular bleach to maintain the elevated SLAM level noted on the FC/CYA Chart. Once you pass the SLAM, then you can resume normal operations with the SWG. Good you caught it early. :goodjob:
 

revitup

Bronze Supporter
Nov 30, 2019
315
Pawleys Island, SC
Thanks, you may have misunderstood my question though. I intend to follow the slam process, elevating the FC level using liquid chlorine. I'm thinking that continuing to generate FC with the SWCG during the slam will help maintain the elevated slam FC level.
 

CrystalRiver

Well-known member
Jun 19, 2020
235
Massachusetts
The SLAM process instructions say to turn off the SWCG, in interest of simplicity. It doesn't hurt to leave it on during SLAM, *as long as you turn it off for OCLT.* Too many people don't follow every instruction, leave the SWCG on for OCLT, think they passed, and then wonder why everything goes downhill when they let chlorine levels drop to normal.
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
I'm thinking that continuing to generate FC with the SWCG during the slam will help maintain the elevated slam FC level.
Generally we recommend just leaving the SWG off since it's not designed for SLAM maintenance and may be a bit of waste unless you will be away for an extended period of time during the SLAM. You also want to be careful that with the chlorine doses, the SWG doesn't increase the FC too high.
 

revitup

Bronze Supporter
Nov 30, 2019
315
Pawleys Island, SC
Slam completed successfully. Passed criteria including the OCLT this morning. FC Was 29 at 7:30 last night and measured 29.5 at 6:30 this morning.
This leads me to another question. After testing I added another gallon of 10% LC this morning anyway just because it was there. I didn’t measure but pool math says that would have brought FC to 41 or so (1 gal = 12 ppm) and the app has been very accurate in predicting FC level for the slam when I’ve checked. Checked FC 5 hours later and it was 28.5. Trying to understand why I would lose 12 ppm FC in 5 hours in a algae free perfectly clear pool. Is it that excess chlorine burns off exceptionally fast in sunlight when it’s way above normal CYA/FC levels?
 

JJ_Tex

Bronze Supporter
Jul 17, 2019
1,537
Prosper, TX (DFW)
Slam completed successfully. Passed criteria including the OCLT this morning. FC Was 29 at 7:30 last night and measured 29.5 at 6:30 this morning.
And you double checked that the SWCG was off? Just asking because your FC went up, oh and it is the title of the thread. Hopefully it is turned off and you are done.