New with question about salinity

[ScottReefer]

Hi all, new here and have a question about mixing new salt water. Should I make sure the water is as close to 77 degree's when testing salinity of newly mixed saltwater? I've read that the temp has to be 77 degree's for you to properly get a reading of 35 ppm if mixed correctly. Sorry if this is in the wrong discussion. First post on any forum .

 

[725196]

Heat and cold will effect the salinity of the mix. My suggestion is shoot for the same temp you keep your tank(s) at. 77° is a good target but don’t worry if you are a degree or two off high or low.

 

[725196]

By the way welcome to R2R.

 

[NashobaTek]

Welcome to the team

 

[Purkey Pets]

This depends on the measuring device. Some refractometers have auto temperature correction.

77F or 25C is usually the standard reference point though, it's best to measure at that temperature.

 

[Reef.]

I mix my salt water when the water is at room temp, I bring it to 35ppt, when I need it, I heat to tank temp, I recheck the salinity, it is normally still the same salinity, just make sure the container stays covered.

Red Sea salt actually recommends you don’t mix the salt with RO water above 20c/68f.

 

[Randy Holmes-Farley Verified Community Expert]

To be clear, temperature has no effect on salinity. Temperature does mess with some ways of measuring salinity, and not with others. So you need to understand how you are measuring salinity, and whether the device you are using is negatively impacted by temperature changes.

 

[ScottReefer]

Thanks everyone for the info. I have a refractor with ATC but noticed a difference in salinity when testing my new mixed water at 77 to 80 degrees than the usual 72 to 74 room temp I usually mix at. It was higher by a couple of points (36 to 37 ppm). I know I’ll never have perfect numbers but would like to have a consistent method that produces somewhat of the same results every time I mix if possible.

Thanks again everyone. I really appreciate all of the help. Glad we have a community like this to go to for knowledge.

 

[Randy Holmes-Farley Verified Community Expert]

Thanks everyone for the info. I have a refractor with ATC but noticed a difference in salinity when testing my new mixed water at 77 to 80 degrees than the usual 72 to 74 room temp I usually mix at. It was higher by a couple of points (36 to 37 ppm). I know I’ll never have perfect numbers but would like to have a consistent method that produces somewhat of the same results every time I mix if possible.

Thanks again everyone. I really appreciate all of the help. Glad we have a community like this to go to for knowledge.

That implies the ATC is not perfect. While it is not likely the reason why the ATC is that far off (poor design/manufacture is more likely), what you are using is likely a refractometer intended for sodium chloride solutions, not seawater, and thus its temperature corrections are not exactly designed for seawater.

Also, be sure to calibrate it with a 35 ppt standard, not RO/DI.

 

[JReef85]

Welcome to R2R! I almost never heat my saltwater prior to mixing it cause my refractometer auto adjust for temp. If I'm doing a big change for some reason and the new saltwater is really cold I will warm it up first.

 

[BeltedCoyote]

Welcome to R2R!

 

[Reef.]

Thanks everyone for the info. I have a refractor with ATC but noticed a difference in salinity when testing my new mixed water at 77 to 80 degrees than the usual 72 to 74 room temp I usually mix at. It was higher by a couple of points (36 to 37 ppm). I know I’ll never have perfect numbers but would like to have a consistent method that produces somewhat of the same results every time I mix if possible.

Thanks again everyone. I really appreciate all of the help. Glad we have a community like this to go to for knowledge.

that difference could be down to not cleaning or cleaning the refractometer between tests, or using a pipett that again is not clean, the slightly bit of residue left between tests can affect the results, cleaning the glass on the refractometer with RO will help but again make sure it’s dried or that too will alter the result.