Should I buy a Refractometer or Hydrometer?

[Rich Klein]

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

I’d second that vote.

 

[Badblackdog]

Which should I buy?

Purchase a refractometer and also purchase a bottle of calibration solution. Check the calibration every time you use it.

 

[FernBluffReef]

Hydrometer for me. Refractometer went to the trash pile (ok never use again back shelf) almost as soon as I bought it. Refractometer = useless and unreliable - for me - no matter how often calibrated.

I also use a Hanna Salinity checker for day to day as it’s quick and accurate. I’ve found the calibration fluids to be inconsistent so what I do is mix my water using the Hydrometer (Tropic Marine) and then use that water of known (to me) value to calibrate the Hanna Salinity checker. I change water every three weeks using the TropicMarine and recalibrate as needed which isn’t all that often.

I’ve also had very good luck with swing arm hydrometer - used them for 30 years and alway consistent for me to the TropicMarine . I only got TropicMarine after returning to the hobby and everyone knocking swing arm hydrometers in favor of refractometers. So I bought Refractometer and quickly returned to a swing arm as I just could not get reliable results using the refractometer… which cause me to question them both

 

[SuzieD]

Which should I buy?

I used a hydrometer and it was WAY OFF! My salinity was at 0.34! It killed off all of the bacteria in my newly cycled tank and killed some of my corals. I found this out after my LFS tested my water with a refractometer. The manager said they won’t even sell hydrometers anymore because of how bad they can be.

 

[Narideth]

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.

This. I used multiple salinity solutions when I was having my salinity crisis, used several salinity measuring tools at the LFS, I never felt like I could trust any of them since the readings were all over the place.

Now I pull out the TM hydrometer periodically and verify that my refractometer is accurate, since the refractometer is so quick and easy to use.

 

[JBNY]

I've been using a refractometer for decades. They are easy to calibrate and take seconds to take a reading. My ICP test I sent out last week came back with Salinity at 34.809, my 10 year old refractometer said I was at 35. They are more expensive than other options but they last forever.

 

[revhtree Verified Admin]

I like to use a refractometer to test against what the controller and hydrometer say. So all of the above!

 

[King Sweetcorn]

I like to use a refractometer to test against what the controller and hydrometer say. So all of the above!

So I should buy a refractometer and a hydrometer? And maybe I can compare them?