I started a SLAM on Sunday and the sun is really doing a number on my FC levels during the day. Yesterday I was losing up to 9ppm in just 3-4 hours but only 2ppm overnite. My CYA was 60 when I started; is it okay to add CYA to help keep the FC from dropping so much during the day? I'm willing to add the bleach to add 4ppm to shock level and hopefully make it up with less loss during the daylight hours if it make sense to do so.
CYA and SLAM
- Thread starter dlwxman
- Start date
Be interesting to see what experts say. I believe you will lose x amount regardless of CYA level. I wouldn’t raise it.
- May 3, 2014
- 58,766
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
Adding more CYA won't fix the problem because you will then have to add more chlorine to compensate, which will then increase your burn off to sunlight. Due to the ratio, during a SLAM you will always see higher solar losses than you normally would.
I will say that it's unlikely that a loss that significant within a few hours is entirely due to sunlight. Even at SLAM levels that's quite a bit of loss.
I will say that it's unlikely that a loss that significant within a few hours is entirely due to sunlight. Even at SLAM levels that's quite a bit of loss.
I thought CYA was supposed to help stabilize the FC level and protect it from sunlight. Apparently I'm not thinking right. I don't quite understand it but I will defer to the experts. Thank you!
When slamming, no matter the CYA, the FC level is always above what the CYA can protect/hold in reserve. X amount of CYA holds X amount of chlorine. I think...in layman's terms. 
