normal chlorine demand?

[irvinenewbie]

Chlorine demand of the pool has been going up. FC has been decreasing by 1.5-2ppm per day. I thought duck feces in the pool had something to do with it. However, no feces today, but still lost 2ppm FC. has been using 6% bleach, just switched to 10% liquid chlorine. FC level has not been going up accordingly. overnight chlorine loss is zero, CC is zero.

pH 7.6
FC 6.5 at 5pm (8.5 before direct sun shine on pool this am)
CC 0
TA 90
CH 360
CYA 40
temp 78F approx

1. what is the "average" chlorine demand per day in southern CA (sunny, mid 70F weather)
2. CYA was 60 in the fall. had tremendous rain in the winter. Is 40 a reasonable number due to dilution?
3. if there is no o/n chlorine loss, CC zero, why is the amount of bleach not bringing up FC level adequately according to the calculator? shelf life of bleach too old?

Thank you.

 

[duraleigh]

Irvine,

I'd say your consumption is just about right. If you've noticed a trend upward recently, I would think it is due to the warming of your water temp. Answering your questions.....

1. On this forum, 2ppm seems about average for an outsdoor pool

2. Absolutely reasonable....splashout may have contributed as well.

3. Not sure I understand the question, but very old bleach (say, from last year) will be weakened.

 

[frustratedpoolmom]

Ditto, what Dave said...

 

[poolgirl22]

I am losing between 1.5 and 3 a day, holding at night, and I live in S. Indiana!!! So your daytime loss seems great to me! lol!
I get sun from 9am to 6pm so...

 

[irvinenewbie]

Thanks! i feel better now.