Refractometer Suggestions

[Elliott]

I use the double D brand noted above

Each time I use it I take a cup of sample water from the tank, pull water from it with a rubber dropper, discard it and repeat that a couple more times to get any remaining salt out of the dropper from before (believe me it makes a difference!)

Then I test the sample. Then I test R0 water and if for example it shows one bar above the zero mark, I then subtract one bar from my sample reading.
So each time I use it I make an adjustment if needed. Works well for me.

The most important thing about salinity is to keep it stable.

 

[coralreefdoc]

Elliott. Im impressed with your level of precision/attention to detail ! I thought I was the only one around so methodical

Excellent choice in Refracs ... I own/utilize the same unit, as a 2nd/3rd form of salinity measure/comparison tool. Again, "methodical perfectionist" ...

While I use RO-DI as a quick determinant, 53mS calibration solution is the benchmark. Agree with your statement, regarding consistency/stability of salinity, as you'd rather have a steady elevated or deficient 1.027/1.024 than ever fluctuating 1.026/1.024/1.027/1.025/etc.

 

[Elliott]

Elliott. Im impressed with your level of precision/attention to detail ! I thought I was the only one around so methodical

Excellent choice in Refracs ... I own/utilize the same unit, as a 2nd/3rd form of salinity measure/comparison tool. Again, "methodical perfectionist" ...

While I use RO-DI as a quick determinant, 53mS calibration solution is the benchmark. Agree with your statement, regarding consistency/stability of salinity, as you'd rather have a steady elevated or deficient 1.027/1.024 than ever fluctuating 1.026/1.024/1.027/1.025/etc.

Hi coralreefdoc :wavehand:

Yes, agreed, and it's amazing how little it takes, a bump for example, to throw off the accuracy of a refractometer. I have a Sybon that I use to double check once in a while

 

[tatuaje08]

With refractometers, and this applies to pH probe as well, you always want to do a two point calibration. For a refractometer this means calibrating with R.O. water first then using a 1.026 calibration fluid, dialing in to the 1.026 to get an accurate reading, and using the difference from the RO water to let you know how off the instrument is off all together.

With pH, same concept. You calibrate to the solution that is close to what you are monitoring (the aquarium water 10.01, and Ca reactors 4.01). Then verify with 7.01 solution. The more the two numbers deviate, the closer it is time to buy a new pH probe.

So if I calibrate mine to 0 with rodi, and then I use solution and it matches to 1.026 on the dot, then is it safe to say I can only use rodi from that point on?

 

[tatuaje08]

I use the double D brand noted above

Each time I use it I take a cup of sample water from the tank, pull water from it with a rubber dropper, discard it and repeat that a couple more times to get any remaining salt out of the dropper from before (believe me it makes a difference!)

Then I test the sample. Then I test R0 water and if for example it shows one bar above the zero mark, I then subtract one bar from my sample reading.
So each time I use it I make an adjustment if needed. Works well for me.

The most important thing about salinity is to keep it stable.

I just dip mine directly in the water. Works every time. :thumbsup: