Favorite refractometer?

[Fish Think Pink]

Just remember it has a claimed accuracy of +/- 2 ppt, so a reading of 35 ppt could be anything from 33 to 37 ppt (sg = 1.0249 to 1.0279).

Randy, what do you personally use?

I was hoping if I used it with specific gravity it would have less margin for error. https://media.cdn.bulkreefsupply.com/media/wysiwyg/PDFs/Milwuakee Digital Refractometer Manual.pdf

 

[Fish Think Pink]

I have found the VeeGee STX-3 the best comprimise of cost and quality. My Milwakee digital meter broke after a year and the red sea is not nearly as accurate as this one. I recommend this one highly if you plan to use it long term.

that resembles my discontinued Milwaukee MR100ATC - glad there are options like that still around

 

[Timich]

Been using redsea for about 5yrs, seems it's accurate.

Question, do you calibrate to 0 ppt or 0 sg. Or let's say I wanna use sg, do I calibrate to 0 sg or still 0 ppt?

 

[Timich]

I have found the VeeGee STX-3 the best comprimise of cost and quality. My Milwakee digital meter broke after a year and the red sea is not nearly as accurate as this one. I recommend this one highly if you plan to use it long term.

Yes got one. I've calibrated it at 20c with 20c rodi water like it stated. It was also already pretty much calibrated when I got it. Before I use it in my room to test tank water, room at 77f and ato water around 68-70f, the reading is slightly lower 0ppt. Atc on meter doesn't adjust. Nor do my other 2 I have. Do you have this problem?

 

[chadfish]

I have found the VeeGee STX-3 the best comprimise of cost and quality. My Milwakee digital meter broke after a year and the red sea is not nearly as accurate as this one. I recommend this one highly if you plan to use it long term.

What makes this one better than one of those $20 versions?

 

[Randy Holmes-Farley Verified Community Expert]

Yes got one. I've calibrated it at 20c with 20c rodi water like it stated. It was also already pretty much calibrated when I got it. Before I use it in my room to test tank water, room at 77f and ato water around 68-70f, the reading is slightly lower 0ppt. Atc on meter doesn't adjust. Nor do my other 2 I have. Do you have this problem?

How much lower?

Remember, it only claims +/- 1 ppt

 

[Koigula]

What makes this one better than one of those $20 versions?

The view is bigger and clearer than the budget version. I use the aquacraft standards as my perception is they are the most reliable.

I can not really photograph the difference but it is stable and easy to adjust. Amazon is returnable usually. I bought direct from my area as they were on sale under 99. These analog devices with a bright incandescent bulb are bit better than +/- 1 ppt.

Doing a quick and dirty measurement system analysis of the digital Milwakee digital refactometer instrument showed to me it was more expensive and less accurate. It is digital so must be correct(?) if yours even works after a year or so.

 

[Randy Holmes-Farley Verified Community Expert]

Randy, what do you personally use?

I was hoping if I used it with specific gravity it would have less margin for error. https://media.cdn.bulkreefsupply.com/media/wysiwyg/PDFs/Milwuakee Digital Refractometer Manual.pdf

I use a conductivity meter. Specifically, an old Orion model 128 with a 4 electrode probe. Some folks get them on ebay.

I don't think the choice of unit impacts the margin of error.

 

[Randy Holmes-Farley Verified Community Expert]

Question, do you calibrate to 0 ppt or 0 sg. Or let's say I wanna use sg, do I calibrate to 0 sg or still 0 ppt?

If those are not the same (0 ppt and sg = 1.0000), there's a fundamental problem with the device.