Clarification on Ozone vs. UV---High daily FC loss

kimkats

Mod Squad
LifeTime Supporter
Jul 10, 2012
47,360
Tallahassee, FL
Jumping in to say what a PRETTY pool you built! LOVE the design and tiles!! Everyone else has you on a good path for figuring out the mystery of the FC lose.

WHEN you get a SWG get one rated for DOUBLE your pool size! Means less electric use from pump run time and helps your cell last longer this way.

Kim:kim:
 
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Krysib

Well-known member
Jun 18, 2020
51
League city TX
Jumping in to say what a PRETTY pool you built! LOVE the design and tiles!! Everyone else has you on a good path for figuring out the mystery of the FC lose.

WHEN you get a SWG get one rated for DOUBLE your pool size! Means less electric use from pump run time and helps your cell last longer this way.

Kim:kim:
thanks Kim!!!!!!

We are very happy considering we had no idea what we were doing!!! I have read to double the size for SWG-and have already researched pricing. Now to convince the hubs!!
 

JJ_Tex

Bronze Supporter
Jul 17, 2019
1,865
Prosper, TX (DFW)
Dang, with 1.5 overnight loss I think you are right to start the SLAM. Based on the pics and your logs, its nothing that has a strong foothold, so it should be a quick one. Keep it at 24 for a few days (until you pass the 3 criteria) and you should be good to go.
 
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Krysib

Well-known member
Jun 18, 2020
51
League city TX
Thanks JJ Tex!

so justa quick question......I am trying to target 24 based on my cya. So get to 24 and check several times a day to bring it back to 24? Or overshoot 24 and don’t let it drop below?
 

JJ_Tex

Bronze Supporter
Jul 17, 2019
1,865
Prosper, TX (DFW)
Great question. I dont know the SLAM article by heart, but if I was able to test and adjust chlorine every few hours I would shoot for 24. If longer than that, I would cheat and go a bit higher.
 
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mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
33,864
Laughlin, NV
The SLAM level FC is based on science such that the active chlorine at those levels stays below the level with 1 ppm FC and 0 CYA. That results in the level being safe for finishes, materials, and people. Going above the SLAM level FC makes those items susceptible to damage, and is a large waste of chlorine as UV will quickly attack that excess FC.
 
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Krysib

Well-known member
Jun 18, 2020
51
League city TX
Ok-so far today I’ve added 4 gallons of bleach and testing somewhere around 18ppm FC.

Just added another gallon. Hoping that’ll get it to 24.

Just checking-is 6 gallons or more reasonable per day?

also-gonna assume that’s whatever Crud is in my pool eating the chlorine faster than I can put it in. (Right?)
 

Krysib

Well-known member
Jun 18, 2020
51
League city TX
Ok-I’ve added 11gallons if 10% bleach since yesterday. Enough to add 71 ppm according to pool math.
I just upped my pool volume to 15k gallons (vs 14k) in the calculator as I seem to not quite be making it to 24ppm as needed.
Just want to make sure I’m on the right track! (??) Bought 12 gallons of bleach yesterday thinking that would last longer-off to Wally World for another refill.
 

Krysib

Well-known member
Jun 18, 2020
51
League city TX
I’m still going through bleach like it’s water——should I try an OCLT tonight or wait until the bleach consumption is more stable???? Or is it just that it’s being consumed by the suns UV?
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
33,864
Laughlin, NV
Have you checked all potential hiding places? Skimmer doors, light niche, etc? As I posted above, with you saying the water is crystal clear, an OCLT is warranted.
 
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Krysib

Well-known member
Jun 18, 2020
51
League city TX
Thanks Marty!! We have checked all the skimmers,lights and cleaned out the pump basket. Never saw a hint of anything. Pool is clear. Just took the last sundown test and cc was 0.

turned off pump and all ozone/uv. Will check FC and CC at 6:30.

Thanks for your continued help and guidance!!!!!!
 

Krysib

Well-known member
Jun 18, 2020
51
League city TX
I think I might have messed up last night. I turned off the pump for last nights OCLT test due to not being able to turn off the UV sanitizer.
I know I should leave the pump running 24/7 during a SLAM but with the OCLT should I turn it off?

I can turn it down to 25% and that decreases the flow enough such that it doesn’t trigger the UV,but any higher and it’s an always on type of thing.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
33,864
Laughlin, NV
OCLT is best done with the pump running or at least you need to run the pump for 30 minutes before testing in the morning.

Where is that thing wired to? Cannot it not be turned off at all?