is 5ppm FC loss in a day normal?

[rastoma]

I did overnight loss test and lost 0ppm FC from yesterday evening to this morning. CC still at 0

Kids swam today for about 3 hours. According to local weather data temp got up to 76F today. Pool gets direct sunlight for a few hours.

I don't remember losing that much FC a day last year.

I recently posted numbers from last night, here they are again:

TA=60
CH=0
CYA=50
PH=7.6 (could be 7.8, I'm using a cheap no-name kit for PH right now, have a Taylor on the way).

 

[mas985]

It depends on the FC level. If it is 10 ppm or above, that might be a normal loss. If the FC level is 5 ppm in the morning and 0 at night, that is a different issue.

 

[JasonLion]

With CYA at 50, losing about 50% of your starting FC level over 24 hours to sunlight is normal. With many hours of swimming, additional loses are to be expected. So, 5 ppm might well be reasonable, depending on what your starting FC level was.

 

[rastoma]

sorry... forgot to add that info. It was in my other thread.

Starting FC was 8.

Pool calc says recommended CYA level is 30 to 50, recommended FC is 4-8. My CYA was at 50 so I'm trying to maintain upper level of recommended FC at 8.

I'll need a little more than a gallon of 6% a day I guess.

 

[dmanb2b]

hmm...one gallon...I know that's about 5ppm in 13.5k gals, but that seems excessive. We have the same size pool...pool is exposed to sunlight from 7am-4pm...I never recall burning through that much

If that is truly your chlorine requirement you may be better off just getting an intex swg...that's a lot of bleach

 

[JasonLion]

That chlorine loss makes a lot of sense, given two+ kids swimming for three hours. 50% loss would be about 3-4 ppm to sunlight and an additional 1-2 ppm for kids swimming, give or take.

 

[dmanb2b]

Oh I trust you Jason...just seems like a lot of bleach daily for a 24" pool. Then again every pool is slightly diff and we did use the solar cover a lot which would also help hold the chlorine levels

 

[rastoma]

If that is truly your chlorine requirement you may be better off just getting an intex swg...that's a lot of bleach

Yes and a lot of trips to the store as I don't have a 'handy' place to store 30 gallons of bleach (monthly usage, I hate hauling bleach bottles). And I'm trying to find 10-12.5% for two reasons, hopefully cheaper per ppm and also less storage space.

I also agree about the Intex SWG. I think I see it in my near future in about a month

That chlorine loss makes a lot of sense, given two+ kids swimming for three hours. 50% loss would be about 3-4 ppm to sunlight and an additional 1-2 ppm for kids swimming, give or take.

3 kids actually. At least I know it's somewhat 'normal'. It's ok as long as I know I'm doing everything right. I guess last year I wasn't as consistent as I'm trying to be now. I would just dump some bleach in every day but not check it but once a week. I knew I wasn't putting too much and had to end up shocking a few times because of not adding enough so I'm on top of it this year with knowing exactly how much is used a day.

and we did use the solar cover a lot which would also help hold the chlorine levels

Yeah I want to get a solar cover eventually. I think first I'll get the Intex SWG as it's not a whole lot more than a good cover.