How cold is too cold to mix salt?

[Sean Duggan]

As the title states I’m curious on how cold is too cold to mix salt. I have a fish room that I heat to about 70-72° and I have my rodi and mixing station in there. Do I have to heat the water to my desired 78° before I mix or is that 70-72° okay? I know salinity varies with temperature. I was wondering if this temperature difference will cause a problem.

 

[Randy Holmes-Farley Verified Community Expert]

There’s no concern with dissolving salt in cold water. It may go in more slowly, but problematic precipitates like calcium carbonate are actually less likely to form at lower temperatures.

 

[NanoDJS]

Id say its prob 65 to 68 in the basement where my fish room resides , I mix all my salt cold and then raise the temp. Dont know if that helps , never had any issue .

 

[homer1475]

I never heat my WC water. Just leave it at room temp when mixing and using. For the 10G I change on my 80G tank, it only drops the temp by 5 degrees. And within the hour it's back up to normal temps.

 

[X-37B]

You would have issues below 32°F.
LOL!

 

[Randy Holmes-Farley Verified Community Expert]

I never heat my WC water. Just leave it at room temp when mixing and using. For the 10G I change on my 80G tank, it only drops the temp by 5 degrees. And within the hour it's back up to normal temps.

You drop the temp by 5 deg in a few min?

I too never heated my water from the 60’s, but I also used it very slowly with an auto water changer.

 

[Sean Duggan]

Okay thanks everyone I’ll won’t heat up the water any more than it’s already at

 

[homer1475]

You drop the temp by 5 deg in a few min?

I too never heated my water from the 60’s, but I also used it very slowly with an auto water changer.

Temp in my sump drops by 5 degrees(tank is kept at 78, house is roughly 75), until I turn the return back on and it gets mixed in.

Actual tank temp only drops by like a 1 degree.

 

[Jeeperz]

My salt is mixed at garage temp~40-45 degrees

 

[Randy Holmes-Farley Verified Community Expert]

Temp in my sump drops by 5 degrees(tank is kept at 78, house is roughly 75), until I turn the return back on and it gets mixed in.

Actual tank temp only drops by like a 1 degree.

oh, ok,that sounds better

 

[zapbap99]

warmer faster, colder slower. simple as that i always go heat because i mean plug a 50 watt heater in a 20 gallon brute have it on deck

 

[Randy Holmes-Farley Verified Community Expert]

warmer faster, colder slower. simple as that i always go heat because i mean plug a 50 watt heater in a 20 gallon brute have it on deck

But, calcium carbonate precipitation is more likely in warmer water where it is less soluble. Some salt companies even warn of that.

 

[Reefer40b]

Mine is usually in the 50-60's when i mix mine up!

 

[Jason mack]

Might be a stupid question ......
Doesn't temp affect salinity ...wont it read different at different temps ....I was told this once .

 

[Randy Holmes-Farley Verified Community Expert]

Might be a stupid question ......
Doesn't temp affect salinity ...wont it read different at different temps ....I was told this once .

Temperature does not impact salinity. It does impact some measurement methods, and not others. Depending on what method you use, it either corrects for you (e,g., conductivity) or you need to correct manually (e.g., glass hydrometer).

 

[ReefReadyYouTube]

I mixed salt in water around 50-55 degrees and waited like 30 minutes it was all dissolved and I put it in my tank. Nothing bad happened.

 

[Daddy-o]

I dump the salt in my 40-50 degree water, turn on pump and heater and let 'er mix

 

[Paul J]

I use cold R/O water below 10 degrees overnight, Then add the heater and warm up to 26 degrees.
Check SG and if that's OK it ready to go.

 

[Darren in Tacoma]

I use cold R/O water below 10 degrees overnight, Then add the heater and warm up to 26 degrees.
Check SG and if that's OK it ready to go.

What?? You can't mix water when it's still frozen, then heat it up till it's still frozen!

Oh, wait.....what side of the road do you drive on when you go get your salt?

 

[Jeffcb]

There’s no concern with dissolving salt in cold water. It may go in more slowly, but problematic precipitates like calcium carbonate are actually less likely to form at lower temperatures.

Dose salinity change as temperature rises?