Moon cycles effecting refractometer calibration.

[Tokinreefdose]

I am wondering if moon cycles effect the calibration on refractometers or what common/uncommon things could have caused mine to change cause it was reading lower than actual salinity so ** 1.03 read 1.025.

 

[Garf]

I am wondering if moon cycles effect the calibration on refractometers or what common/uncommon things could have caused mine to change cause it was reading lower than actual salinity so 1.3 read 1.25.

Just guessing that you’ve calibrated it with RODI water, or vampire blood.

 

[EricR]

I am wondering if moon cycles effect the calibration on refractometers or what common/uncommon things could have caused mine to change cause it was reading lower than actual salinity so 1.3 read 1.25.

Moon cycles, that's funny...

I hate refractometers so don't use 'em but others might have input if you provide the type (make/model) you're using and how you're calibrating it.

*assuming you meant 1.025 vs 1.030

 

[Tokinreefdose]

Calibrating with rodi 0 ppm water manually. Will update with make and model later this day.

 

[Lbrdsoxfan]

I am wondering if moon cycles effect the calibration on refractometers or what common/uncommon things could have caused mine to change cause it was reading lower than actual salinity so ** 1.03 read 1.025.

What does a moon cycle have to do with a mechanical instrument. You have to routinely calibrate it. Especially if it's a variance of one of these....

You stare at them funny and they loose calibration.

 

[EeyoreIsMySpiritAnimal]

You stare at them funny and they loose calibration.

You're not kidding!!

 

[Charlie the Reefer]

Those commonly used refractometers are calibrated mechanically via turning a screw on the top of the device.

It's regular for them to lose calibration, even after one day of use. If you just toss it lightly on a table, it can throw off the calibration. I keep 35PPM salinity calibration fluid on hand at all times and calibrate it every time before use.

 

[Tokinreefdose]

Just guessing that you’ve calibrated it with RODI water, or vampire blood.

Great guess am I supposed to use distilled? Or water with some sort of ppm/mineral content?
So everyone is on the digital I suppose where you can callibrate with rodi?

 

[Lbrdsoxfan]

Great guess am I supposed to use distilled? Or water with some sort of ppm/mineral content? What's the most efficient way to calibrate the manual refractometers. So everyone is on the digital I suppose where you can callibrate with rodi?

Sigh... As said above, you need refraction fluid to calibrate to 35ppt There is also a diy solution you can make.

You don't calibrate with only RODI.

 

[Charlie the Reefer]

Great guess am I supposed to use distilled? Or water with some sort of ppm/mineral content? What's the most efficient way to calibrate the manual refractometers. So everyone is on the digital I suppose where you can callibrate with rodi?

I don't like the digital ones. It's really easy to calibrate them! You can use 0 TDS RODI water and the "wrench" thingy those refractometers come with. Just take the rubber cover off the calibration hole and turn it until it reads 0 PPM on your RODI.

It's more reliable to calibrate it with saltwater you KNOW is 35PPM (calibration fluid, really cheap and easy to order).

Also make sure your refractometer is clean before any use, because obviously residue can throw off your readings.

 

[Alexwlwsn]

Get something like this for calibration:


You're using your refractometer to measure salt water so you want to calibrate it with something as close to your salinity goal as possible. Yours is currently accurate at 0ppm and gets less accurate as salinity increases.

 

[Tokinreefdose]

Get something like this for calibration:


You're using your refractometer to measure salt water so you want to calibrate it with something as close to your salinity goal as possible. Yours is currently accurate at 0ppm and gets less accurate as salinity increases.

Well if I got this I would still then set it at 0? I suppose my understanding is since the water has saline properties but on a microcausim so it's not void of minerals Id still be okay setting at 0. I did notice the rodi water is difficult to see the blue line solid with for grounding out the 0 point calibration.

 

[trevorhiller]

You need to make refractometer calibration solution to calibrate it instead of using RODI water.

Add 18.941 grams of Morton Table Salt to 500 mL RODI Water

Reference this: https://reefkeeping.com/issues/2004-06/rhf/index.php

 

[Tokinreefdose]

Will this solve my concerns or is their a more safe accurate measuring medium?
Dr. Marine Glass Saltwater Hydrometer Thermometer Reef Soft Coral https://a.co/d/0oBB3IG

 

[trevorhiller]

The refractometer you have WILL work. If you are concerned with accuracy, make the DIY soltion and calibrate it before each use to ensure it hasn't drifted.

Every style has a margin of error, even the style you posted requires temperature compensation.

I know people like the Tropic Marin floating one or I use this one: VeeGee Scientific STX-3 (which is actually designed to be calibrated with RODI water, it's the only one I have seen made to do that)

​

 

[strawberryfish]

Will this solve my concerns or is their a more safe accurate measuring medium?
Dr. Marine Glass Saltwater Hydrometer Thermometer Reef Soft Coral https://a.co/d/0oBB3IG

The tropic marin version is a better bet but much more expensivebulkreefsupply.com/high-precision-hydrometer-tropic-marin.html?utm_term=&utm_campaign=EL+%7C+EXP_Conversion_Search+%7C+DSA>+Global&utm_source=adwords&utm_medium=ppc&hsa_acc=7373341438&hsa_cam=17047231420&hsa_grp=136889117478&hsa_ad=594719631021&hsa_src=g&hsa_tgt=dsa-627157874527&hsa_kw=&hsa_mt=&hsa_net=adwords&hsa_ver=3&gclid=Cj0KCQiA37KbBhDgARIsAIzce17QHdcXilQy6DvXmziuowihYNggcPUjLlcywGCe6NvdZRlraNrpu9gaAjMxEALw_wcB

 

[Alexwlwsn]

Well if I got this I would still then set it at 0? I suppose my understanding is since the water has saline properties but on a microcausim so it's not void of minerals Id still be okay setting at 0. I did notice the rodi water is difficult to see the blue line solid with for grounding out the 0 point calibration.

Idk what half of your comment here means but you'd set the line to 35ppt after adding drops of that fluid to the glass.

 

[EeyoreIsMySpiritAnimal]

Well if I got this I would still then set it at 0? I suppose my understanding is since the water has saline properties but on a microcausim so it's not void of minerals Id still be okay setting at 0. I did notice the rodi water is difficult to see the blue line solid with for grounding out the 0 point calibration.

If you use something you know has 0 salinity, you would set it to zero. If you use something you know has 35ppt salinity, you would set it to 35... As others have mentioned, calibration using 35ppt solution is going to give you the most accurate result when you measure your tank water or fresh saltwater, but using 0ppt (RODI, distilled, etc) can at least keep things consistent. Before mixing new saltwater, I calibrate my refractometer using a Tropic Marin glass hydrometer, and then use RODI before every test while adding salt and dialing in the salinity. Final test with the Tropic Marin if it's a large water change.

 

[EeyoreIsMySpiritAnimal]

Those commonly used refractometers are calibrated mechanically via turning a screw on the top of the device.

It's regular for them to lose calibration, even after one day of use. If you just toss it lightly on a table, it can throw off the calibration. I keep 35PPM salinity calibration fluid on hand at all times and calibrate it every time before use.

As mentioned above, I literally check the calibration before EVERY use, even if I'm mixing and testing a new batch of SW multiple times. I think my screw might be loose [insert joke here!] because it's been known to drift even when I've handled it gently.

 

[Tokinreefdose]

As mentioned above, I literally check the calibration before EVERY use, even if I'm mixing and testing a new batch of SW multiple times. I think my screw might be loose [insert joke here!] because it's been known to drift even when I've handled it gently.

Alright I've ordered a lab grade high percision hydrometer and 35ppt solution from brs. Will be cross comparing my readings. 35 ppt would be the numbers on the right then? I was under the assumption 35 ppm of salt to remedy the, "vampire blood" rodi water. I clearly can see now left is sg specific gravitiy right is ppt parts per thousand.