Is My Refractometer Busted?

[DocRose]

Looking for opinions here on what step I should take. I've had this refractometer for about 8 years now. However, 6 of those years it spent in storage being untouched. I pulled it out about a month ago to use again. I've been using it for about a month, and getting steady readings of 1.026. However, once my new tank was cycled, I took a water sample to one of my LFS just to have them double check my parameter readings. He told me (using an instant read digital salinity meter) that it came out to 1.019. I picked up some calibration fluid and went home.

First, I re-tested my tank's water and it came out at 1.024. I placed some pure RO/DI water on my refractometer and calibrated it down to 0. Placed the calibration fluid onto it, and it was already at the proper lever based on the calibration bottle 1.0264. Wiped it clean and tested my tank water again, and again it came out to 1.024. A few days later I went to a different LFS and asked them to test it. They did so (using a refractometer), and he got a reading of 1.021. When I went back home, I tested one more time using my own, and I still got 1.024.

In essence the readings from the different places are...

My Refractometer - 1.024
LFS #1 Digital Salinity Meter - 1.019
LFS #2 Refractometer - 1.021

I'm unsure of what to think/do at this point. I don't want to spend money on a new refractometer, if there's really nothing wrong with my own (it's never been dropped or damaged in any way), and it's maybe the two LFS that have improperly calibrated devices. Advice?

 

[Dcal]

Looking for opinions here on what step I should take. I've had this refractometer for about 8 years now. However, 6 of those years it spent in storage being untouched. I pulled it out about a month ago to use again. I've been using it for about a month, and getting steady readings of 1.026. However, once my new tank was cycled, I took a water sample to one of my LFS just to have them double check my parameter readings. He told me (using an instant read digital salinity meter) that it came out to 1.019. I picked up some calibration fluid and went home.

First, I re-tested my tank's water and it came out at 1.024. I placed some pure RO/DI water on my refractometer and calibrated it down to 0. Placed the calibration fluid onto it, and it was already at the proper lever based on the calibration bottle 1.0264. Wiped it clean and tested my tank water again, and again it came out to 1.024. A few days later I went to a different LFS and asked them to test it. They did so (using a refractometer), and he got a reading of 1.021. When I went back home, I tested one more time using my own, and I still got 1.024.

In essence the readings from the different places are...

My Refractometer - 1.024
LFS #1 Digital Salinity Meter - 1.019
LFS #2 Refractometer - 1.021

I'm unsure of what to think/do at this point. I don't want to spend money on a new refractometer, if there's really nothing wrong with my own (it's never been dropped or damaged in any way), and it's maybe the two LFS that have improperly calibrated devices. Advice?

could be any. i cant think of a easier or simpler option than pick up a swing arm hydrometer or like a 10-20 refractometer and see what it reads

 

[DocRose]

could be any. i cant think of a easier or simpler option than pick up a swing arm hydrometer or like a 10-20 refractometer and see what it reads

Dug out my old hydrometer and it read between 1.022 and 1.023.

 

[Reef.]

No reason to trust an LFS more than yourself.

Search for Randy's diy calibration fluid and make your own, bottles ones can be off.

Maybe buy a Tropic Marin Hydrometer, you can then use it to check your refractometer, the hydrometer is very easy to use and no need to calibrate it.

 

[DocRose]

Maybe buy a Tropic Marin Hydrometer, you can then use it to check your refractometer, the hydrometer is very easy to use and no need to calibrate it.

I thought about grabbing one of those. I just hate that I would have to power off all powerheads and pumps to use it.

 

[Reef.]

I thought about grabbing one of those. I just hate that I would have to power off all powerheads and pumps to use it.

not if you buy a 500ml measuring cylinder.

 

[Arego]

They weren't meant to stick into a tank with water movement even from fish. Get a separate container then dump the water back in..

 

[Reef.]

They weren't meant to stick into a tank with water movement even from fish. Get a separate container then dump the water back in..

yeah good point, even fish movement will make the result hard to read as the scale is so accurate, would be a shame to not get an accurate reading because of movement.

 

[DocRose]

not if you buy a 500ml measuring cylinder.

Tips on where to snag one?

 

[KStatefan]

Tips on where to snag one?

Amazon

Amazon product

 

[Reef.]

Tips on where to snag one?

remember to have the testing salt water at the calibrated hydrometer temp, if you buy the Tropic Marine it'll be written on the side, mine is 25c, yours could be 77f, if the salt water you test is not at that temp you either need to let the temp drop or raise it (stand in a dish of hot water) or use a hydrometer salinity correction calculator,

Salinity Correction Calculator

Aquarium calculator; Correct a relative specific gravity (sg) measurement taken with a non-temperature-correcting unit.

www.hamzasreef.com

I only recommend using the calculator if the temp is only slightly away from 77f, more than a few degrees off I prefer to bring the salt water to temp as I feel it's more accurate.

Sounds a bit daunting but it really isn't, you soon get in the swing of it, my tank is 25.5c time I get the water in the cylinder it's 25c.

 

[redfishbluefish]

One more thing you might wish to consider, especially after sitting in storage, is to lubricant your refractometer. Check it out here:


Lubricate Your Refractometer