The "Best" Refractometer?: My experience with several popular devices

[trevorhiller]

I just picked up the Milwaukee and so far I'm not a fan. So far it’s been inconsistent - the calibration fluid reads perfectly at 1.000 but the validation fluid which is supposed to read 1.025 SG reads 1.029 consistently. Let’s just put the fluid aside (bad batch?) and go with tank water, it reads "correctly" - 1.025 on my handheld refractometer and 1.025 on the unit. But worries me for the future - having trouble deciding whether to return it and get something else or trust in it.

Practical, money saving advice first:
Just pick a number, test frequently and keep it dialed in on it. You’ll be fine with the Milwaukee.

Obsessive advice second:

I wasn’t impressed by the Milwaukee myself—an accuracy of +/- 2 ppt wasn’t very impressive to me.

If you’re set on knowing the “real” value like I am, I can’t recommend the Misco or the VeeGee enough.

Salinity is so important and one of the most critical numbers in a reef tank in my opinion so it’s worth spending the money to me.

Food for thought…. People are spending hundreds of dollars on automatic testers for nitrates and phosphates yet there are successful reef tanks with both high and low nitrates/phosphates.

On the other hand, people cheap out on their refractometer or put little thought into salinity but I’d challenge you to find one successful tank that says their salinity swings all over the place. They don’t exist from what I’ve seen.

The Misco is one of the best “reefing gadget” purchases I’ve made and salinity is almost a non issue now. I pick up on swings way before they ever become a problem for the inhabitants and can correct them rapidly because how precise it is. If the Misco is too expensive for your budget, the VeeGee is the next best “budget friendly” device that is solid, repeatable and accurate as I recommended in the original post.

 

[SanFernandoValleyAIOReef]

This is 100% right, calibrate before use but that's not a con. That is a standard for all refractometers.

I use a refractometer and a floating swing arm. My swing arm I check every couple years but it's always right on, not needing to calibrate everytime.

I plan on getting one of the 20$ (17$) Amazon refractometer, how would I calibrate it without buying the BRS 35ppt liquid? Using Rodi water? Also I buy my rodi water from lfs, how can I make sure it’s actually Proper rodi water in buying?

 

[Dburr1014]

Why make your own;

https://reefkeeping.com/issues/2006-12/rhf/

And how to make your own;

https://reefkeeping.com/issues/2004-06/rhf/index.htm#:~:text=Salinity%20(PSU),-3.3&text=This%203.65%20weight%20percent%20sodium,mL)%20of%20purified%20fresh%20water.

 

[Snoopy 67]

I have one from National Industrial Supply now for years.
Whenever I check it's still correct.

 

[Lonely reefer's]

I plan on getting one of the 20$ (17$) Amazon refractometer, how would I calibrate it without buying the BRS 35ppt liquid? Using Rodi water? Also I buy my rodi water from lfs, how can I make sure it’s actually Proper rodi water in buying?

I compared calibration fluid with ROID water, it read similar

 

[zoomonster]

I was just looking at that.
to bad is so fragile..

LOL Believe it was the 3rd attempt from BRS before I got one not broken in its case. Still have one that is seldom if ever used anymore. Just a pain to get a good float and accurate reading.

 

[zoomonster]

I too have used a variety since the 90's including the near useless instant ocean swing arm (although got by with it for years). I have salinity on Apex but absolutely useless other than up/down trends. Still have a refractometer too. Currently using and like the Hanna. I calibrate maybe once a month or if mixing water and usually rinse it in RO. Couldn't be any easier than hitting the calibrate button and sticking it in a packet of solution. I bought a 25 pack last time from BRS.

 

[Ryebreadiest]

Honestly anyone serious about salinity should have a glass tropic Marin hygrometer. They are cheap, flawlessly accurate and never need calibration. Mine lives in the rigid plastic tube it came in. Feed mode to kill flow, slowly set it in the water and read. It’s not my daily way of checking but I do it once a week to ensure my Milwaukee is on target.

 

[Pistondog]

I use the milwaukee, calibrated with Randys diy morton salt solution. It reads high by 0.001, but is consistent. You have to let the water sample reach the same temp as the instrument, which takes a couple of minutes.