Differentiating salt parameters???

[Humuhumununu]

I'm currently mixing my Red Sea Coral Pro Salt (a.k.a. the only salt in the world that goes by weight instead of cups) and I when I mixed it in last night the ppt read 31 and the Specific Gravity read 1.022. However this morning ( when the pump wasn't running, it read 29 for the ppt, and 1.020 for the Specific Gravity. I am using a Milwaukee Electronic Refractometer and did calibrate it each time. So in short: Do the statistics of salt change if its being stirred, and are electroic refractometers accurate/reliable? Thanks.

 

[RockStacker]

The salt might not have been fully dissolved when you initially tested the salinity and the sample you got could have been a pocket of higher salinity.
Even though the powder is no longer visible, it still takes some time for the salt to fully dissolve.

My personal preference is to have the newly mixed saltwater churn in the bucket with a powerhead for at least 24 hours before I add it to my tank.

 

[Bifferwine]

+1 RockStacker. It's advised to let the water mix for 24 hours before testing for specific gravity. It's not going to be accurate if you measure it right away, or before it has mixed sufficiently.

 

[Bifferwine]

But if you think about the difference between 1.020 and 1.022... Assuming you are doing 10% water changes, adding 10% of water that is just a little off from what your tank is (say 1.025 or something) isn't going to make much of a difference at all.

 

[RockStacker]

But if you think about the difference between 1.020 and 1.022... Assuming you are doing 10% water changes, adding 10% of water that is just a little off from what your tank is (say 1.025 or something) isn't going to make much of a difference at all.

Slippery slope :mrgreen:

 

[Bifferwine]

Not really. :mrgreen: If 90% of your water is at 1.025 and 10% is at 1.022, that means the resulting water is 1.0247. Is there a big difference between 1.025 and 1.0247? Nope, not nearly enough to be concerned about.

 

[motorcyclereefer]

I thought I finished this type of calculations when I dropped out of Quantitative Analysis. But yes Sarah is right. There is barely any perceptive difference in .0003 of a change. With other stuff in life it might be bad but for salt water it isn't going to make a difference. And besides its withing the +- 5% so I wouldn't worry.

 

[bjohanson1234]

Also, does your electronic refractometer compensate for temperature? Or do you have to do some calculations?

 

[Humuhumununu]

It does have a thermometer.