The heat is killing my Pool.

[Deb04]

FC 7
CC 0.5
PH 7.5
TA 50
CH 275
CYA 70
Salt 3400

We went away for two weeks last month. We had a pet sitter who we asked to empty the skimmer. We have an SWG so that seemed sufficient. She seems to have done that. While we were gone there was a week of 100° weather. (pls note I live in NH and this is unusual.) When we came home, the pool was a little cloudy. I SLAMmed until I met all 3 criteria. At that point the CYA was 60.

we’re having another heatwave, in the 90s. Lots of sun and humidity. my pool is at 86° which is the highest it’s ever gotten. The highest I’ve ever raised it with the heater is 84. It got to 86 (from 72) naturally. When the heat came back, I noticed that the SWJ wasn’t able to keep up. Increased it from 60% to 80% running 8 hrs per day and increased the CYA to 70. Today I noticed the water is dull again. Some algae dust on the floor. I went and bought some 12.5% liquid chlorine. I’m going to start slam tomorrow.

I’ve never had this sort of pool behavior before. It really seems like it’s the heat and that I just need to keep the FC higher when we’re having a heat wave. Does that make sense?

Yes, 90’s is a heatwave in NH.

 

[mknauss]

You are not generating enough chlorine to cover the loss due to UV. Run the pump longer when you need more chlorine.

 

[proavia]

You have a SWG rated for a 40,000 gallon pool - if the SWG is run at 100% for 24 hours per day.
With a 19,000 gallon pool, you may have to run the SWG at close to 100% for 12 hours per day or some other combination of SWG percentage and pump runtime to provide the required chlorine output.

 

[Deb04]

You have a SWG rated for a 40,000 gallon pool - if the SWG is run at 100% for 24 hours per day.
With a 19,000 gallon pool, you may have to run the SWG at close to 100% for 12 hours per day or some other combination of SWG percentage and pump runtime to provide the required chlorine output

Agreed but I normally keep the % at 40%, maybe 60% in mid summer with pump running at 6-8 hours. . The only thing that’s different is this extended period of heat, unless I’ve got some hidden algae. I’ve looked in the normal hiding spots and not found it.

I guess my question is, does increased heat (not Sun, as we have Sun every summer) increase need for FC. I don’t have much experience with this.

 

[cledee]

Agreed but I normally keep the % at 40%, maybe 60% in mid summer with pump running at 6-8 hours. . The only thing that’s different is this extended period of heat, unless I’ve got some hidden algae. I’ve looked in the normal hiding spots and not found it.

I guess my question is, does increased heat (not Sun, as we have Sun every summer) increase need for FC. I don’t have much experience with this.

We've kind of had a dry summer in New Hampshire especially on the coast, with a lot of mostly sunny days, will cause a higher chlorine loss.
Warmer temp water allows for faster algae growth.

You mentioned that you had cloudy water last month. Maybe you didn't fully clear it and the SWG is keeping it at bay.

 

[Deb04]

Thank you. That was what I needed to know.

I know those of you in the Deep South are laughing at me re 90-102 being a heatwave. That’s ok. Makes up for when you guys get an inch of snow and it closes the state and all of us northern New Englanders .

 

[an1vrsy]

I live in hot, hot Las Vegas. Triple digits for the past 2 weeks. Excessive heat warning for the past 10 days.

Our pool water has been hovering at 86* - 88* degrees and that is when running our glacier chiller. A couple of days we didn’t turn the chiller on the water got up to 92*.

I say all of this to document that when I tested FC and it started dropping from our normal 8 - 10 down to 6 - 7, I checked CYA and added 10 ppm. After that CYA increase I turned the IC60 down to 50% and now we are still trending high
FC 10 - 11. Is it heat? Or a drop in CYA? My vote is check your CYA and raise it 10 ppm.

 

[proavia]

I guess my question is, does increased heat (not Sun, as we have Sun every summer) increase need for FC. I don’t have much experience with this.

Yes
I'm near Phoenix AZ. Right now it's 3pm - 115 F and 13% humidity. Pool is 92. It's been 110+ for over 2 weeks. I am going to bump my CYA up 10 ppm tomorrow.

Your extended heat is going to use a bit more chlorine.
Keep an eye on your CYA as well. Higher water temps will result in a decrease on CYA.

 

[Newdude]

This last week and change was brutal. I haven't pulled the trigger to 80% yet, but 60% is bringing me way further into the single digits than I like. Like an 8.

I KNOW !!!! As IF !!!!!

I'm // thisclose to losing it at any given moment. I should just go to 80% and save myself

 

[Davegnh]

I'm in the same boat I usually bump it up about 25% during these heat waves. It's definitely been a hot couple weeks pool's been running 88f. Bumped it up 50% from my normal level. I can't complain it's been an awesome few weeks for the pool. It's always better to be safe than sorry with a little extra chlorine.

I normally run at 20% for 24 hours a day I get sun pretty much Dawn to dusk this keeps my chlorine from 6-9ppm. With a CYA of 80.