At What Temperature Should I Open Pool/Michigan

Mendy48

Bronze Supporter
Apr 27, 2018
939
Midland, MI
Hello! It's been a while that I've been on this site. I'm so happy to be back. I see that the website is different (looks awesome). It will take some time to get used to it.

I had a question... I'll like to schedule my pool opening soon and was wondering when I should open my pool. The temperature outside is in the 40s, but I'm thinking of opening my pool in the 60s. What's your opinion on this? I know there's an answer to this question somewhere on this website, but I can't find the link.

Thanks.
 

rajung

Well-known member
Mar 17, 2015
463
Cedar Falls, Iowa
Check water temp first.
Have it running before water temp stays in the 60 deg range, algae starts to happen at that temp. Kind of a tough call for me when I open.One day the water temp is 58, close to 60 and the next few days its 45 for a week after cold spring rain. I usually have to get my pool up and running earlier than most since I don't cover it, and that gets a little cold on the hands in April, usually around the 3rd week. Water still has about 8 inches of ice with this freakish winter we had, started in Jan and hammered us constantly into this month.
 
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Mendy48

Bronze Supporter
Apr 27, 2018
939
Midland, MI
Check water temp first.
Have it running before water temp stays in the 60 deg range, algae starts to happen at that temp. Kind of a tough call for me when I open.One day the water temp is 58, close to 60 and the next few days its 45 for a week after cold spring rain. I usually have to get my pool up and running earlier than most since I don't cover it.

I have to buy a pool thermastat. Ours broke. I didn't know I needed to check the water temp first and not necessarily go by the temperature of the atmosphere. Learn something new all the time. What type of pool thermastate is recommended. I had mine for only one year when it broke. It wasn't a digital one, but the kind that you have to read and floats in the water.
 

rajung

Well-known member
Mar 17, 2015
463
Cedar Falls, Iowa
That's what I have. The more accurate one is on my heater which I remove in the fall for storage. The floaters are ok, but not the most accurate , not sure as a digital one goes. Never used one. Between heater water reading and floater, the floater usually shows 4-5 deg warmer.
 

Mendy48

Bronze Supporter
Apr 27, 2018
939
Midland, MI
Gotta... Yeah! I have a heater and I usually get my pool temp from that. However, it's unplugged for now. I guess I can get a new floater thermatat for now and call it a day. That way, I know my pool temp in advance.
 

mknauss

Mod Squad
TFP Expert
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May 3, 2014
37,211
Laughlin, NV
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Do you have an instant read digital meat thermometer? Use that for a guess. You can always open sooner than later. Only issue is you do not want any extended periods of below freezing temperatures once your equipment is fired up.
 

Mendy48

Bronze Supporter
Apr 27, 2018
939
Midland, MI
I have a thermostat for my pH calibrater but that’s about it.
I’m looking at our weather here and it’s going to steadily climb from here on out. So the pool temperature will, indeed, start to climb.
Will the pH thermostat work for now... after I calibrate it? Or should I just buy a pool thermostat ASAP?
 

mknauss

Mod Squad
TFP Expert
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May 3, 2014
37,211
Laughlin, NV
Pool Size
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Chlorine
Salt Water Generator
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Any thermometer will work that can read the water temperature.

The water temperature in an inground pool surprisingly aligns with the average overnight temperatures. So if you overnights are in the 50's, the pool water will be pretty much in the 50's. If you are seeing more overnight temps in the 50's than 40's, probably time to open the pool. I would suspect you still have a few weeks before that happens.

Get a pool one if you need it for the season. If not, then as long as the weather is done being below freezing at night, schedule them to open the pool.
 
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Leebo

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Jul 21, 2011
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I’d go ahead and call now to schedule your opening. If your area is like ours the schedules will fill up quickly. You’ll need to kinda watch the temps some to make sure there’s no extended periods of freezing but looking at the time of year it’s a risk I personally would take.
 

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Aug 5, 2016
8
Temperance, MI
I live in Southeastern Michigan just north of the border. May 1st is my target date. Unless the temperature really kicks up, the pool temp will stay under 60 by then and you won't have to worry about freezing temperatures as well. My 10 day forecast where I'm at is still showing lows in the 30's for the next 10 days. I opened April 28th last year. The water temperature was still in the 50's when I opened.
 

scdaren

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May 20, 2018
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Clovis, CA
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Any thermometer will work that can read the water temperature.

I have one of those thermal gun thermometers, where you can point it at something, and it tells you the temperatures. Honestly, we use it mostly to play with our cats because it has a little red dot laser pointer thing they like to chase.

Point being... if I point it at my pool it is pretty darn accurate reading the water temperature. And super easy, I can do it from my kitchen. They go for under $20 on Amazon.
 
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Mendy48

Bronze Supporter
Apr 27, 2018
939
Midland, MI
Any thermometer will work that can read the water temperature.

The water temperature in an inground pool surprisingly aligns with the average overnight temperatures. So if you overnights are in the 50's, the pool water will be pretty much in the 50's. If you are seeing more overnight temps in the 50's than 40's, probably time to open the pool. I would suspect you still have a few weeks before that happens.

Get a pool one if you need it for the season. If not, then as long as the weather is done being below freezing at night, schedule them to open the pool.

Scheduled my pool opening! The overnight will be in the 40s then, so it's a perfect time to open it. Can't wait.
 

ship of fools

Well-known member
Nov 9, 2011
642
Albany, NY
Do you have an instant read digital meat thermometer? Use that for a guess. You can always open sooner than later. Only issue is you do not want any extended periods of below freezing temperatures once your equipment is fired up.

If it's below freezing for a period of time just run the pump and the water won't freeze. People run bubblers near the docks in the winter where I icefish and it can be 15 or 20 below and the water won't freeze as long as the bubbler is running.

Obviously you don't want to open it with a month of winter left but a few below freezing nights won't hurt anything. I had a diver come a few years ago to fix some leaks and he told me he had just done a pool that had not been winterized and believe it or not there was no damage.
 

Divin Dave

TFP Expert
LifeTime Supporter
Oct 2, 2013
5,687
Longview, Texas
You can open the pool when there's no more danger of it freezing over. With the water temp still low, it will be easy to get the water chemistry in good shape and prevent any algae from starting up.

The recommended opening water temp is 50F, but nothing wrong with opening it sooner.
Waiting until the water temp is higher means bigger risk of more work and more money to bring the water into good shape.
 

mommark

Silver Supporter
May 29, 2014
144
Midland, MI
We just opened our pool. Took the winter cover off and filled with water to the correct level. Tested our chemicals and they are spot on.
 

Mendy48

Bronze Supporter
Apr 27, 2018
939
Midland, MI
We just opened our pool. Took the winter cover off and filled with water to the correct level. Tested our chemicals and they are spot on.
Nice! Yeah! I'll be opening my pool up next week. I can't wait. I'm curious to see how it looks. I'm TFP all the way, so I'm confident that all will be well.
 

toofast

Well-known member
May 9, 2013
993
North East Ohio
50 degrees and perfectly clear....even it it drops to 30's outside overnight, water circulating at 50 will not freeze.

if you wait, you begin to risk algae....
 
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mickey4paws

Bronze Supporter
LifeTime Supporter
Apr 10, 2009
727
S.E. MI
Hey fellow Michigander :) We usually open our pool mid May and water temp is usually around 50. This year we're opening end of April because we're having work done on the pump, and also have a leak and leak detector appts fill up quick I guess.

I have one of those thermal gun thermometers, where you can point it at something, and it tells you the temperatures. Honestly, we use it mostly to play with our cats because it has a little red dot laser pointer thing they like to chase.

Point being... if I point it at my pool it is pretty darn accurate reading the water temperature. And super easy, I can do it from my kitchen. They go for under $20 on Amazon.

Thanks! Never knew such a thing existed. Sounds handier than the one we have that we tie to the ladder and then push it down so it sinks.
 

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