My pool cover fell off mid-winter and this is the first time I’ve ever had to deal with a green pool at the start of the season. I’ve slammed before but only once. I had ZERO CYA this morning before starting. I added about 40oz of CYA in a sock in the filter. At last check I was up to about 25ppm. I added 3 gallons liquid shock and my FC is at 26. Should I let the rest of the CYA dissolve, or keep it around 25 for the remainder of the slam? First pic was at 4:30pm, second pic at 8pm.
Raise CYA before SLAM?
- Thread starter LynnDi
- Start date
You can yank the sock and set it in a plastic bucket for the duration, consider your CYA 30 and target 12 FC from now on. Higher FC is wasteful -- the sun will steal a greater share at higher FC.
Or let it dissolve, consider it 40 (or whatever you targeted) and then maintain the appropriate FC. That's 16 FC for 40 CYA. If you choose to leave it in, you don;t need to wait for it to dissolve to keep on SLAMming
Either way works.
Or let it dissolve, consider it 40 (or whatever you targeted) and then maintain the appropriate FC. That's 16 FC for 40 CYA. If you choose to leave it in, you don;t need to wait for it to dissolve to keep on SLAMming
Either way works.
If there’s anything left in the morning I’ll take it out and test it again. One more question, should I turn off the SWG during the SLAM process? I have it on now thinking it would help keep the FC level up.
Turn it off. You won't be able to judge how much bleach you're really using.
Okay, I’ll turn it off now. My FC went up overnight from 26 to 29. I took out the sock this morning. I’m between 30 and 40 CYA. I was shooting for 24 FC because that’s the minimum for SWG SLAM. Now that I’m already so high, should I let it fall to 16 and then maintain there?
- May 3, 2014
- 58,821
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
SLAM level FC is 40% of CYA. Your CYA is 40 ppm. SLAM level FC is thus 16 ppm.
There is no such thing as 'SWG SLAM' FC level. When you are in the SLAM process, the fact that the pool has a SWCG is immaterial.
Yes. Keep checking every couple hours and when FC gets below 16, you can add more bleach to bring it back up. Whether you have a SWG or use bleach normally makes no difference in SLAM level. That's only dependent on CYA. If you have 40 CYA, you target 16 FC.