Salinity driving me nuts

[shred5]

My tank has definitely seen better days. I've compared my salinity to 2 other pretty successful tanks. I bought 2 different calibration fluids and if I calibrate using them my salt is about .027. The other tanks that use RODI to calibrate read .021 on my refractometer. I seriously don't know what to believe. Anyone else experience this? If I were to use RODI to calibrate it I'd be sitting at about .032.

Yes I have..
Always use calibration fluid not ro/di or distilled water.
I have had refractometer fluid off too..
So far Salifert seems to be in the middle of them all and consistent.
Always make sure the calibration fluid is same temp as tank. Make sure you shake the bottle for a bit and discard first few drops.
Always clean the refractometer so no residue salt is left.
Make sure the refractometer is warmed up and not cold.

 

[CraigMixedReef]

Agree with the Milwaukee digital recommendation - they are excellent devices!

 

[ramona]

I make my own calibration solution with 0.365 grams of pickling salt in 9.63 ml RODI water and keep it in a syringe and use WAOAW Digital Milligram Scale 50 X 0.001g Reloading Jewelry Scale Digital Weight for measuring the salt. Is it wrong?

 

[ramona]

and calibrate to 35 ppt

 

[redfishbluefish]

Have you seen this crazy article about lubricating your refractometer?

Lubricate Your Refractometer


Make sure the little door swings very freely.

 

[CoralCache]

It is weird to me that people don't use the Tropic Marin floating hydrometer at least for back up. It is more accurate than anything else on the hobby level and never needs calibrating.

 

[ramona]

Have you seen this crazy article about lubricating your refractometer?

Lubricate Your Refractometer


Make sure the little door swings very freely.

I did lubricate with WD-40 on Qtip after reading that article, boy what a difference it made.