Should I buy a Refractometer or Hydrometer?

[King Sweetcorn]

Which should I buy?

 

[Ef4life]

Tropic Marin hydrometer or equivalent

 

[GHOSTLY]

Refracometer from Amazon, 24$ and it'll last forever. No need for the fancy name brands

 

[rtparty]

Glass hydrometer or swing arm?

 

[Euphylliaphyle]

Glass hydrometer or swing arm?

https://www.bulkreefsupply.com/high-precision-hydrometer-tropic-marin.html

 

[Euphylliaphyle]

Which should I buy?

https://www.bulkreefsupply.com/high-precision-hydrometer-tropic-marin.html

 

[King Sweetcorn]

https://www.bulkreefsupply.com/high-precision-hydrometer-tropic-marin.html

How do you use this one?

 

[AgentKooper]

I’d vote neither and go with a Hanna salinity checker.

 

[dnprall]

How do you use this one?

You put in the saltwater container and once it stops bobbing, you can read the specific gravity. Very accurate.

 

[King Sweetcorn]

You put in the saltwater container and once it stops bobbing, you can read the specific gravity. Very accurate.

So I just fill it up with water, (Make sure there are no bubbles of course.) Then I get the salinity?

 

[slogan315]

You fill a tall container, like a beaker, with salt water. This thing floats upright in the water. When it is still, wherever the waterline meets the measurements is your salinity.

It’s definitely the most accurate but least convenient way. Many find a refractometer with calibration solution is a good balance of convenience and accuracy. And some of the electronic solutions like Hanna and Milwaukee seem too inconsistent to trust IMO (I have both and choose the refractometer over these)

 

[King Sweetcorn]

How often is it wrong?

 

[Ef4life]

How do you use this one?

A 500ml graduated cylinder is what I use, fill it up with salt water and float the hydrometer

 

[slogan315]

How often is it wrong?

If you mean the refractometer, it depends on the quality of refractometer you buy. But my $30ish one tends to hold calibration for a while, as long as it doesn’t experience any big temp swings.

for the electronic salinity meters, I started having to calibrate them very often to trust their readings at all. By the time you have to do all that, the refractometer is just easier.

 

[Naekuh]

id say get both....

It helps you double check incase u go... HUH?!?!? and you will sometimes go HUH?!?!

I have all 3... a hydrometer, those OG instant ocean one.... a refractometer, and my hannah digital. I use the hannah and refracto more then the hydro.

 

[AgentKooper]

If you mean the refractometer, it depends on the quality of refractometer you buy. But my $30ish one tends to hold calibration for a while, as long as it doesn’t experience any big temp swings.

for the electronic salinity meters, I started having to calibrate them very often to trust their readings at all. By the time you have to do all that, the refractometer is just easier.

My experience is the opposite. I’ve never had a refractometer that didn’t need to be calibrated with every use. I check my Hanna salinity meter against a test solution once a month and rarely need to calibrate it. Takes 10 seconds to test my tank water or salt mix, about 1/20th of the time it takes to calibrate a refractometer, run a test, and then run another one to confirm, calibrate again because the results didn’t match, and then test a third time. My refractometers have been at the back of a shelf in the basement for a couple years now.

 

[sjfishguy]

100% the tropic marin hydrometer. I have been fooling around with the refractometers for years thinking they are accurate. Too many variables can be off: calibration fluid off, calibration off, you think it’s calibrated but lost calibration. The hydrometer is 100% accurate 100% of the time. It’s just physics.

 

[NanoSteam]

You want both, I have both as well ... Reason being the TM Hydrometer is not convenient to take out and use on a regular basis and it's fragile. I just use it from time to time now to make sure my refractometer isn't acting up or they my calibration solution has gone bad. It's a sanity check.

 

[Jimbo327]

Hydrometer for truth. Hanna or refractometer for everyday use.

 

[Randy Holmes-Farley Verified Community Expert]

Most methods are suitable when properly calibrated, but I use neither of these devices. I use a conductivity meter.