Need help with salt checking asp

[THE REEF WHISPER]

Hey everyone,
Long-time lurker, first-time poster here. My soft coral-heavy reef (mostly leathers, zoas, mushrooms, some xenia and nems) has been running stable for over 2.5 years with no major issues—everything grows well, fish are active and eating great, no unexplained losses or stress signs.
I've been using this old triple-scale beer & wine hydrometer (calibrated @60°F/15.6°C, the one with the little wine glass logo) for salinity checks. It consistently reads around 1.026 SG, and I've stuck to that for top-offs and water changes.
Recently picked up a cheap ~$17 ATC refractometer (with the app for reading the scale/photo). After calibrating it with RODI (reads ~0) and testing tank water, it shows 1.030 SG consistently. Big difference!
Quick specs:
Tank temp: ~78°F
Livestock: Soft corals thriving, fish happy (active, good colors/appetite)
No sudden changes—evaporation topped off as usual
Haven't used proper 35 ppt calibration fluid yet (planning to grab some)
From reading old threads here (like the big "Refractometers or Hydrometers: Why the Latter Should Contain a Warning" article and tons of discrepancy posts), it seems brewing hydrometers often read low in seawater due to ionic differences, temp calibration, etc. Many say calibrated refractometers are more reliable for true salinity/refractive index in marine mixes.
But... my tank has been fine at whatever the "real" level is (probably closer to 1.030 if refracto is right). Softies seem to love it, fish no complaints. Stability > perfection, right?
Questions for the experts:
Should I trust the refractometer more and slowly drop to 1.025–1.026 (gradual changes only)?
Or keep doing what works since everything's happy and adapted?
Anyone else use a beer/wine hydrometer long-term successfully, or is it always off by ~0.004 in reefs?
Best way to confirm—LFS test, Tropic Marin hydrometer, or just get calibration fluid and recheck?
Planning to recalibrate the refracto with actual 35 ppt fluid soon and maybe hit up a local shop in CT for a second opinion. Attached pics of the hydrometer for reference.
Thanks in advance—love this community!

I don't know what I should do I did use AI to make a post because I gave it all the info I'm getting stresses about it but it has been doing good for so long useing the Glass hydrometer

Picture

 

[THE REEF WHISPER]

Thank you need help asp

 

[Fish Fan]

The hydrometer for beer and wine is not what you want for your aquarium

Go with an aquarium hydrometer or your refractometer but calibrate it with 35 ppt fluid, not RODI water. You can make your own 35 ppt standard from regular table salt and a decent kitchen scale or even measuring spoons:

Reef Aquarium Salinity: DIY Calibration Standards

Reef Aquarium Salinity: DIY Calibration Standards By Randy Holmes-Farley One of the most important issues facing marine aquarists is providing a suitable environment for their aquaria's inhabitants. Among the important properties for a marine...

www.reef2reef.com

I hope that helps, TRW!

 

[THE REEF WHISPER]

The beer one does work and it has the salt on the side and I have been using it for 1.5 years and everything is doing fine and I don't want to chase numbers and the hydrometer cannot be calibrated or is all ready at 60 F and I do the math with the app

 

[Randy Holmes-Farley]

Did you temperature correct the reading from the beer hydrometer? Or use it on water at 60 deg F?

 

[Randy Holmes-Farley]

The above articles gives you recipes for two different solutions to check those two different devices.

 

[THE REEF WHISPER]

Yes I did

 

[mfinn]

The beer one does work and it has the salt on the side and I have been using it for 1.5 years and everything is doing fine and I don't want to chase numbers and the hydrometer cannot be calibrated or is all ready at 60 F and I do the math with the app

All of the hydrometers for aquarium use I've seen can be calibrated. Get the solution or make your own.
Then once it actually is calibrated, then you will know if your one for beer is right.
When I first got in the hobbie, the floating ones were what everyone used.

 

[THE REEF WHISPER]

Ya ik and people say they're accurate so I really don't know what to believe

 

[dedragon]

tropic marin hydrometer. best way to check to be certain. i use the refractometer when comparing different systems or water changes as it is quicker once you already know the salinity in the tank

 

[Tahoe61]

I use the TM Hydrometer to mix the salt, I mix to 1.026 and to temp 77 f.
Next I calibrate my refractometer to 1.026. Then I calibrate my Milwaukee digital with the 1.026 solution.

I was actually pretty dang surprised how often I need to calibrate the refractometer and the digital.

 

[mfinn]

Ya ik and people say they're accurate so I really don't know what to believe

Calibrate the aquarium hydrometer and you will know.
Who knows it may be already calibrated.

 

[THE REEF WHISPER]

It's is at 60

 

[THE REEF WHISPER]

It's is at 60

It came all ready calibrated

 

[Randy Holmes-Farley]

It came all ready calibrated

Of course it did. But maybe it was done incorrectly. Maybe the person calibrating it got a text on his phone at that moment. Or was daydreaming of his upcoming vacation. Or just got tired of looking at glass hydrometers all day. Maybe the paper slipped inside during transit. Anything.

Most people say it is accurate, but don't actually know. What they really mean is that it cannot be miscalibrated by the user. Not that many have actually checked the accuracy, though I will say the few that I have seen do so find it acceptable.

I don't understand the reluctance to check it. It's quick and costs almost nothing to do so, if you have a scale.

 

[THE REEF WHISPER]

How do I do it

 

[Shirak]

How do I do it

Read the article by Randy that Fish Fan linked above.. Scroll down to specific gravity section for Hydrometers. Recipe there and explains how to test your hydrometer.

There is also a section for refractometer if you want to make some of that and check/calibrate your ATC refractometer. Don't do it with RODI.

 

[THE REEF WHISPER]

Ok I'll do that this weekend and I'll update this post

 

[THE REEF WHISPER]

Hi everyone I have a question

 

[Fish Fan]