how much colder is a salt water pool than reg chlorine?

[outdoorsgal]

I'm disappointed that I have not been enjoying my pool this year. Everyone in Phoenix is glad for the temp under 100 accept for me it seems, since i want to be in the pool. It's 99 degrees today and pump has been off for hours so the water sensor that says 94 is surely not the temp of the pool water. I really like my salt cell but I do not like cold pools which would cause me to consider a different method of sanitizing the pool if there was one besides regular chlorine if they figure that out one day. In the meantime, does anyone know how to do the math on how much colder a salt water pool runs? My pool is 14400 gallons and I could check the salt but last I checked it was within limits, not too much.

Thanks much!

 

[domct203]

SWG pools should have no noticeable difference in temp from the exact same pool when manually chlorinated.

All chlorine pools contain salt.

 

[AimeeH]

SWG pools should have no noticeable difference in temp from the exact same pool when manually chlorinated.

All chlorine pools contain salt.

I couldn't agree more. Your cooler water is likely due to those cooler air temps that you mentioned.

 

[tim5055]

The difference in chlorination methods will not have an effect on the pool temperature.

 

[Teald024]

I'm disappointed that I have not been enjoying my pool this year. Everyone in Phoenix is glad for the temp under 100 accept for me it seems, since i want to be in the pool. It's 99 degrees today and pump has been off for hours so the water sensor that says 94 is surely not the temp of the pool water. I really like my salt cell but I do not like cold pools which would cause me to consider a different method of sanitizing the pool if there was one besides regular chlorine if they figure that out one day. In the meantime, does anyone know how to do the math on how much colder a salt water pool runs? My pool is 14400 gallons and I could check the salt but last I checked it was within limits, not too much.

Thanks much!

Everything about this post confuses me...

94deg pool water is cold??

Do you have a fountain that could be cooling the water?

 

[outdoorsgal]

I was told about ice making water colder by someone recently who said that must be the reason for the pool being colder this year.
They told me of how they were involved in an experiment where salt was added to a bucket of ice water and the water turned colder. This sounded familiar from some time in my childhood as well. I did a bit of research and found the following:

Why Does Adding Salt to Water Make it Colder? | Sciencing
"So how does salt (sodium chloride) make water colder? In essence, it does not. Salt works to depress the freezing point of water so the water can become colder than 32 degrees Fahrenheit (zero degrees Celsius) before it turns to ice. In fact, water containing salt can reach temperatures of nearly minus 6 degrees F."

or more chemistry talk:

solutions - Why does ice water get colder when salt is added? - Chemistry Stack Exchange

I'm no scientist so I'm not sure I understand it too well but it seems as though this only has to do with the freezing point, not water that is 80 degrees.

thx!

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Do you have a fountain that could be cooling the water?

Teald024, I think I had the parascoping fountain on for an hour or so twice this summer. I'm not sure how much cooler the fountain would make the pool after such a limited amt of time? Maybe it's just that night have been cooler in Phoenix this year? thx

 

[AimeeH]

I was told about ice making water colder by someone recently who said that must be the reason for the pool being colder this year.
They told me of how they were involved in an experiment where salt was added to a bucket of ice water and the water turned colder. This sounded familiar from some time in my childhood as well. I did a bit of research and found the following:

Why Does Adding Salt to Water Make it Colder? | Sciencing
"So how does salt (sodium chloride) make water colder? In essence, it does not. Salt works to depress the freezing point of water so the water can become colder than 32 degrees Fahrenheit (zero degrees Celsius) before it turns to ice. In fact, water containing salt can reach temperatures of nearly minus 6 degrees F."

or more chemistry talk:

solutions - Why does ice water get colder when salt is added? - Chemistry Stack Exchange

I'm no scientist so I'm not sure I understand it too well but it seems as though this only has to do with the freezing point, not water that is 80 degrees.

thx!

- - - Updated - - -


Teald024, I think I had the parascoping fountain on for an hour or so twice this summer. I'm not sure how much cooler the fountain would make the pool after such a limited amt of time? Maybe it's just that night have been cooler in Phoenix this year? thx

Salt doesn't make water colder. The addition of salt to water does decrease its freezing temperature so it will remain water (not ice) below 32 degrees.

 

[Teald024]

In addition to the above info, to be totally transparent, adding sodium chloride to water is endothermic (i.e. absorbing heat from the surroundings), but not really enough to be useful at the salt concentration used in a pool.

 

[Griswald]

Salt doesn't make the water colder, it just allows it to get colder. If the temperature outside drops to 28 degrees, salt water can get to 28 degrees, but it won't happen on its own.

 

[outdoorsgal]

I knew this was a good place to ask this question!

Salt doesn't make the water colder, it just allows it to get colder. If the temperature outside drops to 28 degrees, salt water can get to 28 degrees, but it won't happen on its own.

Griswald, So, in the end are you saying that if it's 28 degrees out a salt water pool would get colder than a non salt water pool? thx!

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Salt doesn't make water colder. The addition of salt to water does decrease its freezing temperature so it will remain water (not ice) below 32 degrees.

I don't have to worry about this anyway since there's no way I'm swimming when it's 32 degrees out! thx!

- - - Updated - - -

In addition to the above info, to be totally transparent, adding sodium chloride to water is endothermic (i.e. absorbing heat from the surroundings), but not really enough to be useful at the salt concentration used in a pool.

interesting. maybe this is what causes salt to melt ice? thx!

 

[jblizzle]

The salt level in a pool is not high enough to change the water's freezing point to any noticeable degree.

 

[Teald024]

Griswald, So, in the end are you saying that if it's 28 degrees out a salt water pool would get colder than a non salt water pool? thx!

No! It would not get colder. Adding salt may keep it a liquid water instead of freezing to solid ice (if the concentration was high enough, which it's not in a normal pool)

maybe this {endothermic reaction} is what causes salt to melt ice? thx!

Unfortunately, no. It has to do with the salt ions getting in between the water molecules.
Chem School video off site

Putting salt on ice can make it melt if the ice's temp is above the water/ice transition point
That's why many govt in the Northeast use salt to keep ice off the roads.

 

[outdoorsgal]

I still don't understand it but I knew a few people here would so that's good enough for me! Got up to at least 110 degrees today and I didn't get to get in yet but stuck my hand in to test the water and was feeling warmer. finally! thanks!

 

[Teald024]

I still don't understand it but I knew a few people here would so that's good enough for me! Got up to at least 110 degrees today and I didn't get to get in yet but stuck my hand in to test the water and was feeling warmer. finally! thanks!

Now your just trolling us... 110deg is WAY to hot for not being in the pool.

 

[peterl1365]

Now your just trolling us... 110deg is WAY to hot for not being in the pool.

I imagine she's talking about the air temp. Water temp is likely in the 80's and rising. Even in Phoenix, it will take a while for 14000 gallons of water to warm up after a long winter/spring.