Temperature effect on Chlorine usage

[cliffstone]

My pool is up to 86 degrees and my chlorine usage has increased to around 4-5 ppm each day. Am I getting algae or is the increased sun angle and temp causing this? I check every evening with the FAS/DPD test and raise with bleach to 8ppm. The next evening my reading is 3-4 ppm. A couple weeks ago I was only using 2-3 ppm daily. I have virtually no CC, CYA 40, Ph 7.5

 

[johnd13]

I had the same issues recently. I bumped up my CYA (I have a SWG) and that did the trick for me....

 

[geekgranny]

I just recently bumped up my CYA from 50 to 60. It is working so well that in dumping in my usual every day or two addition, estimating, I'm now overshooting a little more than needed. I like to add enough to take it about 1 level above the top of my range. I've now overshot it a couple of times by 3-4 which isn't too drastic and still below shock. I guess I should test every other day until I know the "almost" exact amount to add. (I do test when the bather load is increased or it rains, which it hasn't in a while, but that doesn't happen often.)

This also gives me a little buffer for when I backwash instead of opening the filter for a hose off. It takes a lot of water to get our "cementous" dust and Fiber Clear flushed out.

gg=alice

 

[JasonLion]

Yes, increased water temperatures increase the amount of chlorine you need to use.

 

[mit43]

I am having the same issue here. My CYA is 80 and the CC went from 3.6 to .4 overnight. The water temp was 92 this morning. We have had extremely hot days here, so I assumed the drop was due to the temp.

Should I run the SWG 24 hrs a day until the temps go down or simply supplement with bleach as needed each morning?

 

[JasonLion]

If your FC level is going too low with a SWG you should turn up the percentage setting. If you are already at 100 percent, you can either increase the pump run time, or manually supplement with additional chlorine.

 

[mit43]

Thanks, Already at 100%. I will increase the run time and supplement as needed. This is our second summer and so far it is much hotter than last year.

 

[kenmccall]

MIT43 you might have another problem if your drop in FC was overnight.

 

[frustratedpoolmom]

I agree, if you are at 100% and that much loss was overnight, even with the SWG on, then you probably have organics consuming the chlorine as it is produced, and you are just one step ahead from an algae bloom.

I would do an overnight test with the SWG off and if you lose more than 1ppm you should shock the pool with bleach.

 

[mit43]

Thanks.

For the overnight test do I test after the sun sets or wait until it is completely dark?

 

[kenmccall]

When the sun sets is fine, just no sun shine on the pool.

 

[mit43]

I did the overnight test and seem to be within the guidelines. I assume the chlorine loss must be related to the extreme heat we have been experiencing.

Over night FC loss was 1ppm from 7.2 to 6.2. Everything else is within guidelines and the water is clear.

FC 6.2
CC .2
TC 6.4
PH 7.4
CYA 65
TA 80
Salt 3800
CH 160