Sure glad I got a refractometer

[Robert Vacchiano]

Same thing happened to me thought I was at 1025 that my swing arm indicated but really it was 1030 when checked

 

[enthejungle]

Where can i get calibration fluid?

I got my last bottle from saltwateraquarium.com. A little cheaper than BRS, 30 day price match, free shipping, and a free trial bag of pellet food.

 

[johnnyenv]

The apex conductivity probe is fine as long as no micro bubbles get into it then it can produce highly inaccurate readings from a few points to 10s of points off. I found a trick was to mount it upside down and that works like a charm

 

[A Toadstool Leather]

My atc refractometer has certainly saved me from potential livestock losses. Too bad it was miscalibrated until I got a solution for it.

 

[Val Shebeko]

Anybody would like to comment ?

The Apex probe measures the conductivity of the water, the refractometer measures the change in the speed of light when it goes from air to water, a hydrometer measures how dense the water is. These are 3 different things you are measuring, none of them is a count of the particles of stuff in a million particles of water. All 3 will give different readings if you dissolve different things, 35.0 ppm of sodium chloride will read different than sea water with 35.0 ppm of stuff in a refractometer.
Our cond probe will not read number to number identically with milwakee's calibration or any other third party tools for checking this measurement.
If you calibrated the Cond probe properly when placed In the 53mS solution it should read around 34.8~35.2. If it did read that after you calibrated it than you successfully calibrated the probe. That's what's important. That it read 34.8~35.2 in the calibration solution from Neptune systems.
Can you put the probe back in the 53mS solution and what does it read? If it does not read within that range then calibrate the Cond probe again. If it did, than you're done.
After that, if you drop it in to a tank or any environment it will read what the conductivity is of that tank. It's not going to be the same as your refractometer, hydrometer, or anything. Our probe reads the conductivity. It's not the same.
To clarify, the conductivity probe functions by measuring the displacement of NaCl ions in the water. The Conductivity probe is not a refractometer. It's not going to read like your refractometer. This is common. It's a conductive sensing probe. Your refractometer is designed to detect specific gravity/density of all the salts in your water like KCl, MgCl, not just NaCl, but the conductivity probe will give you a closer look at the the true salinity (ppt) reading in your aquarium.

Typically most refractometers are not calibrated for Seawater, but a brine solution, thus they are reading the SG/salinity of many other salts in your water other than NaCl. So they will read slightly differently than a conductivity probe which only measures your actual NaCl concentration. Here is ant article on Reef Builders illustrating this discrepancy and points to another article discussing these differences. So it is not uncommon to see this difference between most refratometers and salinity probes.


Here is a great Salinity Calculator the converts ppt to specific gravity and Conductivity
https://www.hamzasreef.com/Contents/Calculators/SalinityConversion.php


Likely the Salinity Probe is being influenced by intermittent EMI. Best way to look into this is logging into the classic dashboard
How to access your "classic dashboard"- Mac
or
How to access your "classic dashboard"- PC

In most cases there will be equipment around the tank that is causing the issue (like an un-grounded ballast, ozone generator, high power/EMI cables routed right next to the Salinity Probe cable, etc.)

Try turning some items off and check to see if it stabilizes your Salinity Probe reading. Assuming that the issue can't be resolved by cable placement, equipment isolation, replacement to the probe, etc. Follow up with us.

 

[Val Shebeko]

Hi Jon,
Yes, I am using
https://www.hamzasreef.com/Contents/Calculators/SalinityConversion.php
While the refracrometer measures 1.025 the Salinity probe is measuring 43.4 ppt which when converted using
The above link gives and equvilent of 1.0328.
I have to order calibration fluid so it will take me a while to be able to recalibrate.
Thanks
Val
Get Outlook for iOS

 

[2Wheelsonly]

Just wait until you go crazy calibrating it!

The instructions that came with my sybon as well as an email directly from the company said to use RODI water OR the pure water solution that came with it to calibrate. My LFS and majority of forums as well as BRS told me to use salinity seawater solution. I get different readings depending on which one I use to calibrate and they are fairly significant. So I just ordered corals from Vivid Aquariums and asked what their salinity was in the shipping water and calibrated to that. If it's good enough for vivid then it's good enough for me!

90% of my corals will come from them anyway so I figure matching their salinity can't hurt.

 

[Val Shebeko]

Hi Val,
Again a Refracometer WILL NOT read the same as a COND probe.
What does the probe read if you place the probe in a cup of tank water outside of your tank?

Will not read the same even if you are converting it from ppt to rsp. ?

In a completely isolated glass the ppt goes from 44.6 to 44. Which is better but not significant.

 

[Randy Holmes-Farley]

When all are properly calibrated for seawater, there will be no difference in the salinity of seawater determined by hydrometer, refractometer, or conductivity meter.

If you get a big difference, something is wrong. A possible culprit is temperature. A conductivity probe must know the temperature to properly calibrate, and if you use something like the Apex where the temp probe remains in the aquarium water, it will give incorrect calibration if the standard is not at that same temp.

 

[Val Shebeko]

Yes even converting the numbers does not take into account that they get there measurements differently
That is why we said this right up front:
The Apex probe measures the conductivity of the water, the refractometer measures the change in the speed of light when it goes from air to water, a hydrometer measures how dense the water is. These are 3 different things you are measuring, none of them is a count of the particles of stuff in a million particles of water. All 3 will give different readings if you dissolve different things, 35.0 ppm of sodium chloride will read different than sea water with 35.0 ppm of stuff in a refractometer.
.6 is not that much of a change in the big scope of things. Remember it is all about trends, not specific numbers.

 

[Randy Holmes-Farley]

Yes even converting the numbers does not take into account that they get there measurements differently
.

How they get their measurements is not, generally, speaking, important. As long as they are properly calibrated, all work perfectly (or nearly perfectly, since minor ion concentration ratio variations are not usually a big deal) and give exactly (or almost exactly) the same answer.

 

[Val Shebeko]

Entertaining this.

 

[ohiojeffsreef]

this is when I changed to a refractometer... my reef wasn't doing well and it was because a float arm was giving me bad information.

 

[DHill6]

Vital Sine is a true seawater refractometer, Drs F&S carry it. You get what you pay for, worth the price.

 

[Sealion]

If you have a gram scale you can make your own calibration fluid. There's a great article floating around the Internet on how to check how your refractometer reads. It's a great artical and when you zero it and then check with your calibration fluid, you then know that what you see is the correct SG as the refractometer reads.

 

[dgrigor02]

+1 for the Milwaukee Electronit Refractometer. Put that on your Black-Friday shopping list as BRS usually puts it on sale for sub $100. One of the better investments I have made for the tank.

I should have bought one years ago with all the eye refractometers repurchased where the pin rusted out for the flapper. It would have paid for itself..

 

[MartinWaite]

According to my hydrometer I was running my tank at 1.026 and after testing with a refractometer I was actually running at around 1.029

Unless you have bought a DD seawater refractometer the chances are you have bought a saline refractometer and the measure seawater wrong and your 1.029 is actually about 1.027. So do you know which you have bought? And if it's a saline one then you can make an allowance for the difference between saline and seawater and as long as you know.

 

[Randy Holmes-Farley]

Unless you have bought a DD seawater refractometer the chances are you have bought a saline refractometer and the measure seawater wrong and your 1.029 is actually about 1.027. So do you know which you have bought? And if it's a saline one then you can make an allowance for the difference between saline and seawater and as long as you know.

The beauty of calibrating with a 35 ppt seawater standard is that it won't matter which type it is. That's why I recommend the standard for any refractometer.

 

[Val Shebeko]

Well following the advice above and ordered up a True Sine from Drs f & s.

 

[Val Shebeko]

Well following the advice above and ordered up a True Sine from Drs f & s.