Please correct me if I'm wrong, but...

[Reggae Fish]

...doesn't the temperature of the water when measuring salinity affect the outcome? I ask because my source of my RO/DI unit comes out very cold. I heat to my ideal temp. and mix with powerhead for a minimum of 24 hours to aerate. How can I get an accurate reading of the salinity if the water is too cold. Should add salt to the best reading and remeasure when it comes to the correct temp.
Now, if I do this, do I need to restart my 24 hours aeration period or is it ok?

Thanks,
Justin

 

[tetra9999]

i think your are right, thats why the salinity testers say "temperature compensation" on them

I think the higher the temp the higher the SG

 

[Daytymer]

Yep, temp affects it.

My RO runs to a 45gal trash can which has a heater and power head in it. It is then attached to the float in the sump. I monitor the SG weekly and adjust if necessary.

The 24 hr aeration thing... well, there are differences of opinion on that. My current setup allows for constant aeration. One of my old tanks was an undrilled 45g tall with no sump and it was lucky to get 5 minutes of aeration. When you're doing one bucket of water at a time, a water change can take forever that way. I don't recommend it, but then again I now have the luxury of a basement setup with lots of elbow room. Not everybody can say that. You have to do what's best in your situation. Good luck!

 

[McBeck]

Refractometers take the temp out of the equation.

 

[dela]

Check out Randy H.F.'s hydrometer calibration article. Temp affect certain types of meters more than others. I think Hydrometers are the least affected while refractometers quickly stabilize the temp since they are only dealing with a few drops of water.

 

[slimer1]

funny this question would come up at this time .Just today I traded some frags for some salt and a pump to run my Berlin proteen skimer in my sump Cris was real helpful thanks . but anyways when I opened the salt bucket on the top of the salt bags was a salinity chart with diferent temperature readings and diferent out comes salinity wise I was thinking to my self man have I been messing up all these years I just always got 50 gals of water to temperature use apower head to mix it up test specific gravity and dumped it in never had any problems that I recall I guess I was lucky but Istill dont plan on changing a thing If it ain`t broke don`t fix it . right?

 

[StupidsReef]

<a href=showthread.php?s=&postid=7101553#post7101553 target=_blank>Originally posted</a> by McBeck
Refractometers take the temp out of the equation.

My Refractometer clearly stated that temp would NOT affect it in any way what so ever as it was designed to adjust automatically. However before I bought one I was forewarned about this issue that most of the cheapy's don't adjust.

 

[DrBDC]

Use the ppt side for the most accurate not the salinity side. I'm not sure the salinity side adjusts for temp but the ppt side does.

 

[dela]

Use the ppt side for the most accurate not the salinity side. I'm not sure the salinity side adjusts for temp but the ppt side does.

Do you have two separate scales on the refractometer? I only have one line down the middle with salinity on one side and ppt on the other. From what I remember, when you calibrate it, there is only one spot to move the entire scale up or down.

I don't know about you guys, but so far I've used this indispensable contraption a total of two times. One to confirm the hydrometer was OK, and one to show someone else how it worked! :lol:

Anyway, I have one of the cheapies.. $40. If you read the fine print, it says to wait 30 seconds for the refractometer and water to reach thermal equilibrium. Also, it is ambient temperature sensitive (I'm guessing ambient temperature will affect the index of refraction of the water) since the unit will reach equilibrium with ambient temp and then the water will match whatever temp the refractometer is at... If I remember I'll read the fine print tonight to clarify what it says. I would be interested in finding out what a "non-cheapy" says. I bet the instructions are very similar.

 

[Mykayel]

As far as the "waiting 24 hrs" goes, there are a lot of people that don't do this at all as the effects of waiting 24 hrs is disputable and vertually negligable if you are only doing small water changes anyway.