My first season of being a pool owner is wrapping up. As of today 11/3/23 my newly built inground gunite pool is still open in central New Jersey. The outdoor temperature dropped to ~27F for a few hours overnight during the past 2 nights but rises back up into the 50's during the day. My pool temperature this morning was the lowest it has ever been at 52F. I have read that the ideal closing temperature to minimize the chance of Algae is less than 50F (and the lower the better). How low can I go in pool temperature before risking issues with the equipment or pipes freezing? I have attached an older front view pic and a more recent back view pic of my equipment. What is the lowest you have successfully let your pool temperature drop down to before closing?
Postponing Closing/Winterizing to the absolute last moment
- Thread starter key1cc
- Start date
- Jul 21, 2013
- 60,151
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Me? Once it was 40 water temp....but it had been a gentle cool down for a few weeks, with no nights below 30, and I kept it circulating 24/7. Family medical issues delayed all other projects. But that day it was windy and snowing, so had to do it. Not fun.
While lower temps do slow down algae, I've uncovered it while still a big block of ice in it. Within a week of the ice melting, I've had algae growing on the sides. Not terrible, but still a pretty green in spots....
While lower temps do slow down algae, I've uncovered it while still a big block of ice in it. Within a week of the ice melting, I've had algae growing on the sides. Not terrible, but still a pretty green in spots....
I also should mention I run my variable speed pump 24/7...1400 rpm during the day and 2400 rpm at night when there are freezing or close to freezing temperatures.
It’s no fun sticking your hand into 40F water to screw on drain plugs.
Another reason I want to wait is because every single day, I have to add muriatic acid to keep my PH from going up in my new plaster pool to high…. And that’s much easier with the pump running to mix the acid in…. I am concerned if I stop to far in advance of the water freezing the PH will rise through the winter and I will have scale
The pH will rise over winter anyway but less with the pump off. If you lower the TA to 50-60 is should stabilize. Mine was just replastered last month and my pH stays about 7.8 all week. Over winter you want the pH to rise a bit to offset the extra cold water which will keep the CSI closer to zero.
I had my alkalinity at 50 for close to a month and my pH continued to rise like clockwork. So I raised in to 70 for the approaching winter and my plan to follow CSI/LSI levels. Currently the pool needs 1/2 cup acid daily to keep it below 8. If I skip a day i need to add a full cup.
My current pool temperature fluctuates between 43 and 46 as the pool does get full sun all day.
My current pool temperature fluctuates between 43 and 46 as the pool does get full sun all day.
I have read that if pH rises above 8.0, that you need to add acid to bring it back down .
However, according to the CSI, it indicates that pH can be allowed to go as high as 9 or more depending on the levels of your chemicals.
I am currently battling rising pH and am trying to get a better understanding of it. To do this I invested in a relatively good pH meter (Ampera 700PH) and I keep the electrode calibrated and regularly check it against known pH standards to insure I keep my 2 decimal place accuracy.
Right now I am holding my pool in the range of 0 to 0.6 CSI. Several days ago, I stopped adding acid and my pH has steadily rose daily from 7.92, 8.07, 8.16, 8.24, and today at 8.31.
Since the water temperature is ~43F the Cl has held at 4ppm (from liquid chlorine) with no additions. My goal is to let the pH go all the way up until it reaches 0.6 CSI to see (and hope) that it levels off and stop rising before that.
Any thoughts are welcome.
However, according to the CSI, it indicates that pH can be allowed to go as high as 9 or more depending on the levels of your chemicals.
I am currently battling rising pH and am trying to get a better understanding of it. To do this I invested in a relatively good pH meter (Ampera 700PH) and I keep the electrode calibrated and regularly check it against known pH standards to insure I keep my 2 decimal place accuracy.
Right now I am holding my pool in the range of 0 to 0.6 CSI. Several days ago, I stopped adding acid and my pH has steadily rose daily from 7.92, 8.07, 8.16, 8.24, and today at 8.31.
Since the water temperature is ~43F the Cl has held at 4ppm (from liquid chlorine) with no additions. My goal is to let the pH go all the way up until it reaches 0.6 CSI to see (and hope) that it levels off and stop rising before that.
Any thoughts are welcome.
I would be ok at a pH of up to 8.3.
I would not go above 8.3, but I don't have a good reason for that specific limit.
CO2 offgassing will stop at a pH of about 8.3.
So, if the pH keeps going above that, you have a source of pH rise like calcium carbonate from the plaster.
Calcium carbonate from the plaster will increase the TA and CH equally, so if you see the same increase in TA and CH, it is probably from plaster dissolving.
I would not allow the CSI to go above 0.3.
I would not go above 8.3, but I don't have a good reason for that specific limit.
CO2 offgassing will stop at a pH of about 8.3.
So, if the pH keeps going above that, you have a source of pH rise like calcium carbonate from the plaster.
Calcium carbonate from the plaster will increase the TA and CH equally, so if you see the same increase in TA and CH, it is probably from plaster dissolving.
I would not allow the CSI to go above 0.3.
- Jun 22, 2014
- 51,580
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
"key", you're still open up there? I'm surprised. If so, when will you be closing?
- Jul 21, 2013
- 60,151
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Postponing Closing/Winterizing to the absolute last moment
My first season of being a pool owner is wrapping up. As of today 11/3/23 my newly built inground gunite pool is still open in central New Jersey. The outdoor temperature dropped to ~27F for a few hours overnight during the past 2 nights but rises back up into the 50's during the day. My pool...
www.troublefreepool.com
- Jun 22, 2014
- 51,580
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Key, I merged your threads to keep the discussion together. Better that way to avoid confusion and cross-talk. 
When I do close , i will drain below the returns so I won’t have to stick my hand in the thirty something degree water I expect to close at.
I don’t have a set time. I will decide based on water temperature and 10 day forecasts. As of now, the next 10 days do not have multiple days in a row where the temperature does not rise above 50F during the day. And, as long as 40 to 50F degree water is flowing through my pipes I can’t see them freezing with temperatures intermittently (for 1 night at a time)in the upper twenties.
It's plenty cold now.. I closed Nov 5th because my SWG shut off (low 50s) Nov 2nd. We've had 20s some nights since, and several low 30s. It's not going to freeze like you said, but it's also not warming up to 60 again. Lol.
We have had the several low 30's and upper 20's here as well, but.........However, It was 65 today in central NJ and going up to 68F tomorrow. I'm trying to stretch it out to see if I can get my pH to stop rising. Since my water is 43F I am not concerned with sanitation to much (my chlorine has been at 4ppm for a couple weeks with no addition needed.) I have stopped adding acid to see how high the pH gets as explained in my merged post (post 10 above)
Still not warming the pool anything appreciable.
Then experiment on !!!!
I had to go until mid Nov last year when my new cover came in. The 1st Saturday after was in the high 30s and cleaning the carts SUUUUUCKED. Food for thought.