Calibrating Refractormeter?

[NanaReefer]

Is there another way of doing it without using store bought fluid?
No LFS around me carries it and I don't want to order just 1 bottle and pay $12 shipping.

 

[stylaster]

Cant you use ro/di and calibrate it to 0?

 

[1guydude]

+1 i just use my ro di water.
Hths
D

 

[senji]

calibration fluid last a verry long time and verry worth it. and check this out way cheaper.

Sybon Seawater Reference Calibration Fluid Salinity Refractometers Monitors | eBay

 

[NanaReefer]

calibration fluid last a verry long time and verry worth it. and check this out way cheaper.

Sybon Seawater Reference Calibration Fluid Salinity Refractometers Monitors | eBay

What's in the fluid that makes it better then RO/DI?

 

[rayjay]

Unless you have a "seawater" refractometer, calibrating using water be it distilled or RO or RO/DI, will give you errant reading at normal salt water levels of 1.026.
Almost all refractometers sold to the hobby are NaCl salt water refractometers.
As our salt water is a mixture of many salts, the refractive index is different leading to error that increases as the s.g. increases. If memory serves correct, you will get a reading 1.0236 when actually the s.g. would be 1.026. Not a big amount, but if you are bent on accuracy then you can either adjust for it or calibrate with the proper fluid. (or you can pay more and get a seawater refractometer)

Refractometers and Salinity Measurement

 

[NanaReefer]

Bought the fluid. Had me some BRS points I forgot about

 

[trido]

What's in the fluid that makes it better then RO/DI?

A little late but for anyone reading in the future.... RO will give you an accurate reading at 0 because the SG is zero. Each refractometer has a variance called the slope. The higher the salinity the greater the slope making the inaccuracy bigger. RO will get you close as pointed out, but it will not get your calibration dead on. Calibration solution accounts for the slope and it holds for a very long time making it worth the investment. If your not worried about accuracy, you might as well use a swing arm hydrometer. I've seen several refractometers be as far off as .03 with RO and then all read accurate when calibrated properly.

 

[NanaReefer]

I guess I should be ashamed but......3yrs reefing and I've never calibrated mine. Except once with ro/di. Just thought I'd try it

Sent from my Kindle Fire using Tapatalk 2

 

[Holygral]

They need calibrated every 3-6 months. They are precise instruments, if you bump them, your reading will be different on the exact salt mix.

 

[1guydude]

I re calibrated mine everytime ive used it...back to 0
Almost like just the room temp change will throw it off.
Its just a vertex nothing spendy.

 

[rayjay]

I re calibrated mine everytime ive used it...back to 0
Almost like just the room temp change will throw it off.
Its just a vertex nothing spendy.

If it is a salt water refractometer, and you are calibrating with water at 0, why bother? Your reading will be incorrect at reefing salinity.
If you were wanting to check for hyposalinity levels below 1.010 then water would give you a closer reading that calibrating with fluid at 1.026.