Losing a lot of FC during the day, is this normal?

[wazzyjazzy]

Thanks to the TFP community, I gained enough confidence a few months ago to tell my pool service company that I would no longer be needing their services, saving me about $115/month.
Numbers have been holding steady for the past two months. However, in the past two weeks I've noticed that my FC is averaging a 8ppm loss during the day.
I've tried doing the Overnight Chlorine Loss Test about 3 times in the past two weeks and I don't see any loss so I'm ruling out Algae.
However, I'll have the FC at 12ppm 8 AM in the morning and when I go to check it at 8 PM, it will measure as low as 4ppm.
It's been really hot here in the Sacramento, CA area, averaging 100 degrees for the past week. Does the higher pool temperature affect FC levels?
I just tested and here are my levels:
FC 4
CYA 40
TA 60
PH 7.5
CH 75

 

[PoolStored]

Thanks to the TFP community, I gained enough confidence a few months ago to tell my pool service company that I would no longer be needing their services, saving me about $115/month.
Numbers have been holding steady for the past two months. However, in the past two weeks I've noticed that my FC is averaging a 8ppm loss during the day.
I've tried doing the Overnight Chlorine Loss Test about 3 times in the past two weeks and I don't see any loss so I'm ruling out Algae.
However, I'll have the FC at 12ppm 8 AM in the morning and when I go to check it at 8 PM, it will measure as low as 4ppm.
It's been really hot here in the Sacramento, CA area, averaging 100 degrees for the past week. Does the higher pool temperature affect FC levels?
I just tested and here are my levels:
FC 4
CYA 40
TA 60
PH 7.5
CH 75

HEY!!! Welcome to TFP!!!

Yep! With a CYA of 40, in Kalifornia, with heat and full sun, I'm not surprised. NORTHERN Ohio here, full sun and swimmers, I can get up to 5.5-6ppm loss. I will ASSume that you are using Liquid Chlorine. If you are, (using liquid chlorine), I would raise your CYA to 50-60 and it will help. If you have an SWCG, then I would raise your CYA to 70-80. In either case, you will likely see a reduction in your Free Chlorine demand.

 

[Katygreys]

I’m in Houston and use liquid chlorine. I would deffffffinitely bump your cya to 50 and honestly 60. Hot as he77 here and zero shade for my pool. You will notice a difference. Make sure you consult cya/FC table for nee targets and minimum if you increase cya.

 

[wazzyjazzy]

HEY!!! Welcome to TFP!!!

Yep! With a CYA of 40, in Kalifornia, with heat and full sun, I'm not surprised. NORTHERN Ohio here, full sun and swimmers, I can get up to 5.5-6ppm loss. I will ASSume that you are using Liquid Chlorine. If you are, (using liquid chlorine), I would raise your CYA to 50-60 and it will help. If you have an SWCG, then I would raise your CYA to 70-80. In either case, you will likely see a reduction in your Free Chlorine demand.

Thank you for the warm welcome!
We haven't had swimmers and I'm still losing 8ppm per day, is that still normal? I've been reading Pool School articles and I see that sunlight consumes chlorine, but I couldn't find anything that said the warm water temp could affect FC as well so thank you for clarifying that.
Yes, I am using Liquid Chlorine (10% 128oz jugs from Walmart)

 

[wazzyjazzy]

I’m in Houston and use liquid chlorine. I would deffffffinitely bump your cya to 50 and honestly 60. Hot as he77 here and zero shade for my pool. You will notice a difference. Make sure you consult cya/FC table for nee targets and minimum if you increase cya.

Alright, I will buy some Cyanuric Acid tomorrow and try to get CYA up to 60. Yes, no shade for my pool either.

 

[Katygreys]

You should definitely notice a difference in FC loss at 60 cya compared to 40. Make sure you do not have an algae issue because slamming at 60 will take a lot more LC than at 40. If you are confident that you’re passing OCLT, than add CYA. be careful not to overshoot it; err on the low side, test a couple days later, add more if necessary. I bet you notice FC loss reduction the next day.

What’s you pool temp? If it’s near or over 90 degF, then search the forum for cya degradation.

 

[Katygreys]

To answer your question about warm weather/heat consuming FC…pretty sure that’s not the case. You’re just getting intense sunlight and UV (hence the warm weather lol) which is eating your FC.

 

[wazzyjazzy]

You should definitely notice a difference in FC loss at 60 cya compared to 40. Make sure you do not have an algae issue because slamming at 60 will take a lot more LC than at 40. If you are confident that you’re passing OCLT, than add CYA. be careful not to overshoot it; err on the low side, test a couple days later, add more if necessary. I bet you notice FC loss reduction the next day.

What’s you pool temp? If it’s near or over 90 degF, then search the forum for cya degradation.

I'm performing another OCLT this evening and will check the FC level early tomorrow morning before the sun hits the pool.
I will measure the pool temp tomorrow afternoon.

 

[Katygreys]

I only ask about the water temp so that you are not surprised by CYA reduction over time if your pool is near or above 90 degF. Check out the last section of this if you have a hot pool

CYA - Further Reading

www.troublefreepool.com