Salinity measuring question?

[josh88997766]

I currently have a plastic hydrometer and I would say it’s pretty accurate just messy my lfs sells brs refractometers with the led with the calibration fluid and a cloth for 40 dollars is it worth it and what makes it more worth it over my hydrometer currently my hydrometer seems pretty accurate always rinse it with non salt water after use

 

[Fish Fan]

If it's a plastic "Swing arm" hydrometer, they are not the most accurate, in my experience. For example, air bubbles on the arm can lead to errors in testing. I think the majority of reefers use a refractometer, they are able to be calibrated, and typically provide accurate and reliable results. I think $40 for a refractometer would be money well spent, but you could find one even less expensive online if you search.

Good luck!

 

[Mr. Mojo Rising]

You seem like you're guessing its accurate, to me its not good enough, I don't trust those plastic swing arms.

 

[jeffmr4]

+1 for getting a cheaper one online. If you get one you can always compare it with your swing arm and see how they fare. I also use a Hanna Temp/Salinity checker which works pretty well. They run about $80 but you might be able to find them used for less.

 

[Pistondog]

use a diy salinity solution to check and you might be able to use most any.
Post in thread 'Ma877 milwauke salinity?' https://www.reef2reef.com/threads/ma877-milwauke-salinity.989442/post-11448814

 

[josh88997766]

If it's a plastic "Swing arm" hydrometer, they are not the most accurate, in my experience. For example, air bubbles on the arm can lead to errors in testing. I think the majority of reefers use a refractometer, they are able to be calibrated, and typically provide accurate and reliable results. I think $40 for a refractometer would be money well spent, but you could find one even less expensive online if you search.

Good luck!

alr also before each use I tap the arm with a wood stick to get air bubbles out and I can see them going out

 

[PopBot16]

I currently have a plastic hydrometer and I would say it’s pretty accurate just messy my lfs sells brs refractometers with the led with the calibration fluid and a cloth for 40 dollars is it worth it and what makes it more worth it over my hydrometer currently my hydrometer seems pretty accurate always rinse it with non salt water after use

Yes, worth it. Just make sure to keep the cap tightly sealed on the cal fluid.

 

[Tahoe61]

My experience with Hydrometers is they don't age well. A refractometer is definitely a significant improvement.
I use a Milwaukee digital, it's been invaluable.

 

[exnisstech]

You really have to have second device to even confirm that the swingarm is accurate.
I've been using this cheap Amazon refractometer for over 8 years. I calibrate with Randy's DIY fluid. I keep a TM hydrometer on hand just in case I get a funky result and want to confirm. Salinty is probably one if the most important parameters so I want an accurate testing instrument.

 

[snorklr]

my vote is for a Tropic Marin hydrometer and a 500ml plastic graduated cylinder from amazon...as long as you don't drop it and break it, it will work forever and you don't have to worry if its calibrated correctly

 

[Fish Fan]

Salinty is probably one if the most important parameters so I want an accurate testing instrument.

^This. Salinity is arguably the most important parameter because when it fluctuates other parameters fluctuate with it. You want to make sure you’re salinity on point for sure.

 

[Fish Fan]

My experience with Hydrometers is they don't age well. A refractometer is definitely a significant improvement.
I use a Milwaukee digital, it's been invaluable.

I love my Milwaukee digital refractometer!

 

[Tahoe61]

I love my Milwaukee digital refractometer!

Yup the best. Boom boom boom all tanks done in a couple minutes.
Easy to calibrate and my adult eyes don't have to guess where the line is.

 

[Fish Fan]

Yup the best. Boom boom boom all tanks done in a couple minutes.
Easy to calibrate and my adult eyes don't have to guess where the line is.

Exactly!

I think RHF mentioned that it’s not quite as accurate as some other options, but I can’t stop using it, it’s so convenient lol! I have the Hanna salinity checker too, but I always go for the Milwaukee :)

 

[Malum Argenteum]

For a long time I was using two swing arm units, and then a refractometer with which I also checked the accuracy of the swing arm units (since they do change over time with build up, I guess). I calibrated the refractometer pretty much every time I used it with a commercial calibration solution.

For about a year ending not too long ago, my reef was doing poorly and I couldn't quite pin it down. Messed with lighting, tried trace elements. Turned out the bottle of calibration fluid I was using was quite far off (learned this when I bought some Biota fish and couldn't quite believe the salinity in the bag -- which turned out to be fine, of course). Now my TM hydrometer is my 'cold dead hands' item (also, I now do two-point calibration on the refractometer, which is another simple sanity check). An incredible tool.