Does 1.026 SP = 35 PPT?

[fftfk]

I always thought 1.026 = 35. No matter how much I calibrate/retest, etc. I can not get 1.026 = 35 ppt on my refractometer. I always end up with 1.026 = .34.

Forgive the blurry picture. I think that is a function of focusing it for eyesight and then trying to take a photo with my camera. It reads 1.026 with a sharp line and and about 34.5 PPT. When I get my water to 1.026 the refractometer always reads just below 35 ppt or even 34 ppt.

Is it a function of my tank water being different than the refractometer stated temp? If so, should I try for SG or PPT measurement?

 

[EeyoreIsMySpiritAnimal]

I always thought 1.026 = 35. No matter how much I calibrate/retest, etc. I can not get 1.026 = 35 ppt on my refractometer. I always end up with 1.026 = .34.

Forgive the blurry picture. I think that is a function of focusing it for eyesight and then trying to take a photo with my camera. It reads 1.026 with a sharp line and and about 34.5 PPT. When I get my water to 1.026 the refractometer always reads just below 35 ppt or even 34 ppt.

Is it a function of my tank water being different than the refractometer stated temp? If so, should I try for SG or PPT measurement?

At 78 degrees fahrenheit, 35 (ppt) = 1.0264 (specific gravity)

 

[EeyoreIsMySpiritAnimal]

Here's a good calculator

Salinity calculator

A unit converter for calculating salinity in marine aquariums. The calculator supports conductivity (mS/cm), salinity (PSU og ppt), density (g/cm³) og specific gravity.

reefapp.net

 

[EeyoreIsMySpiritAnimal]

All that being said, it's entirely possible the numbers or lines on little card in the refractometer are slightly off...

 

[fftfk]

Thank you!

 

[SashimiTurtle]

Maybe I'm blind, but that picture looks like 1.026 = 35 to me.

 

[Sleeping Giant]

looks like it's also not level

 

[TokenReefer]

Ppt and % are not the same thing far as I know

 

[buruskeee]

Yeah the lines are right, 35ppt will read between 1.026 and 1.027 since it’s 1.0264, so naturally 1.0260 will read between 34 and 35ppt.

 

[Uncle99]

Close enough if stable.
I’m sure none is perfect.

 

[EeyoreIsMySpiritAnimal]

Ppt and % are not the same thing far as I know

Of course not... what was your point?

 

[Sleeping Giant]

 

[fftfk]

looks like it's also not level

lol - if there is a trick to get a photo looking through your phone through the refractometer pointed at the light bulb and get it level please let me know!

I guess I could have used the alignment tool in photos to make it appear level.

 

[EeyoreIsMySpiritAnimal]

lol - if there is a trick to get a photo looking through your phone through the refractometer pointed at the light bulb and get it level please let me know!

I guess I could have used the alignment tool in photos to make it appear level.

Yeah, it's not like the line stays horizontal if you tip the refractometer... It reads the same even if you're laying down (although I don't know why you're testing salinity laying down )

 

[Randy Holmes-Farley]

A brine refractometer (which is most common in the hobby) will not line up 35 ppt and sg = 1.0264, while a true seawater refractometer will.

 

[DexterKarin]

I think this answered my question. When people say they target 35 ppt or 1.026 SG it is assumed they mean at 78 degrees as both measures are affected by temperature.... correct?

 

[mook1178]

SG is affected by temp and salinity. Salinity is not affected by temp. Its units are g/kg. SG is basically density of the seawater with g/l as the unit. A liter of water at 78F is not a liter of water at 70F.

 

[FUNGI]

That is pretty much as close to perfect as you are going to get......

 

[KStatefan]

SG is affected by temp and salinity. Salinity is not affected by temp. Its units are g/kg. SG is basically density of the seawater with g/l as the unit. A liter of water at 78F is not a liter of water at 70F.

Specific Gravity is unitless

 

[Miami Reef]

Salinity is not affected by temp.

Actual salinity is not affected by temp, but all the ways to measure it are affected by temperature.