What probe do you trust more?

[Reef Jedi]

I just spent a while calibrating my new Hanna digital salinity pen and also my apex salinity probe.

Hanna = 34.7 ppm

Apex = 35.8

What probe would you trust? I also have a refractometer and just calibrated that. That basically shows right at 35ppm

Can fish or corals tell the difference between these numbers? Or did I just fall down a rabbit hole I don’t need to go down. If I follow the Hanna then I want to slightly increase salinity. But if I follow the apex then I need to go down slightly. If they were closer I feel I wouldn’t be so conflicted.

Overall what would you trust to run your salinity numbers from?

 

[Saltyreef]

Tropic marin high precision hydrometer. Use it once. Sharpie calibrate a cheap deep six hydrometer and use it everytime. Mic drop.

 

[winxp_man]

Another Tropic Marin vote. I use a 500 ml cylinder to get readings. Has yet to let me down. Although high temps will wreck the hydrometer. Don’t ask how I found out.

 

[Gumbies R Us]

I’m also going to say tropic Marin or a Manila salinity checker!

 

[EnterName]

Hanna = 34.7 ppm
Apex = 35.8

HI98319 has an accuracy of ±1ppt

I couldn't find the accuracy of the Apex probes, but 35.8ppt - 34.7ppt is just 1.1ppt, so both probes could very well be within their expected accuracy range. I would say both appear to be operating correctly.

 

[Reef Jedi]

Tropic marin high precision hydrometer. Use it once. Sharpie calibrate a cheap deep six hydrometer and use it everytime. Mic drop.

Another Tropic Marin vote. I use a 500 ml cylinder to get readings. Has yet to let me down. Although high temps will wreck the hydrometer. Don’t ask how I found out.

I’m also going to say tropic Marin or a Manila salinity checker!

Sounds like I need to invest in one and use that as a baseline.

 

[Saltyreef]

Another Tropic Marin vote. I use a 500 ml cylinder to get readings. Has yet to let me down. Although high temps will wreck the hydrometer. Don’t ask how I found out.

Yeah... high precision but at 77 degree water temp lol.

 

[Uncle99]

I trust none. They let me down so many times.
Hard to know when they are truthful or out of calibration, changes happen a little at a time.
That’s why they all just sit on the self.
Just a calibrated refractometer.
It’s never let me down.

 

[Saltyreef]

I trust none. They let me down so many times.
Hard to know when they are truthful or out of calibration, changes happen a little at a time.
That’s why they all just sit on the self.
Just a calibrated refractometer.
It’s never let me down.

Have you ever used a real float hydrometer? Its about as fool proof as you can get.

 

[Uncle99]

Have you ever used a real float hydrometer? Its about as fool proof as you can get.

I have not myself but have heard positive things about them.

 

[Reef Jedi]

Have you ever used a real float hydrometer? Its about as fool proof as you can get.

Do I need anything special to float it in? Does it come with one or do you float in tank?

 

[vetteguy53081]

pin point brand - sure not Apex

 

[Saltyreef]

Do I need anything special to float it in? Does it come with one or do you float in tank?

As said above, it requires a 500ml graduated cylinder but myself just float it in the 5g bucket when i mix water. To be honest, its glass and fairly fragile so what I did was make a bucket of 77degree freshly mixed salt water (measured the salt by weight too) and then took an old plastic coralife swing arm hydrometer and "calibrated" it with a sharpie mark where the swing arm should be pointing. Which was well above 1.025 on its scale. I think it points towards 1.030.

Now, as long as my temp is good, and I fill the bucket to the same level, i know it only takes 25oz of salt by weight to give me perfect salinity. I double check with the cheap plastic swing arm hydrometer for good measure and its always spot on.
No calibration needed, ever. And the fragile glass hydrometer will last virtually forever until my swing arm falls apart and i need to "calibrate" a new one.

 

[BryanM]

The probes that stay in the tank/sump need cleaning and calibrating reasonably often. That was a non-started for me.

I am a tropic marin hydrometer user. Doesn't take that long, and is fool proof, except for teh fragility

 

[Reef Jedi]

The probes that stay in the tank/sump need cleaning and calibrating reasonably often. That was a non-started for me.

I am a tropic marin hydrometer user. Doesn't take that long, and is fool proof, except for teh fragility

Seems like this is the way to go. I keep the tank at 78°. Will it matter testing it at that temp or does it need anything specific or a correction for certain temps?

 

[BryanM]

Seems like this is the way to go. I keep the tank at 78°. Will it matter testing it at that temp or does it need anything specific or a correction for certain temps?

Technically it is calibrated for 77*. I also run my tank at 78, and I just test. No math, no adjustments, and my ICP tests come back with the same numbers I see.

 

[BryanM]

@Reef Jedi btw, I use a graduated cylinder to test. This one from amazon:

Graduated cylinder

I don't like testing in the tank, too much flow and bouncing around, and I don't want to turn all flow off to test.

 

[Randy Holmes-Farley Verified Community Expert]

A calibrated probe is only as accurate as the solution used for calibration, and I would not assume any commercial hobby standards are necessarily accurate.

I’d make a diy or buy a science standard.

 

[winxp_man]

Yeah... high precision but at 77 degree water temp lol.

Does not matter. I use a salinity correction online app that works dead on. Did tests and off by very minimal %. Its to the point it will not make a diff in most systems.


My go to page for many calculators. And they are pretty darn accurate. Had to do a salinity increase and with these calc got it figured out in a jiffy!

https://www.hamzasreef.com/Contents/Calculators/SalinityCorrection.php

 

[Saltyreef]

Does not matter. I use a salinity correction online app that works dead on. Did tests and off by very minimal %. Its to the point it will not make a diff in most systems.


My go to page for many calculators. And they are pretty darn accurate. Had to do a salinity increase and with these calc got it figured out in a jiffy!

https://www.hamzasreef.com/Contents/Calculators/SalinityCorrection.php

I heat my water with a ranco temp controller when mixing since i always mix right before a water change. its easy enough to make sure my water is at temp when checking salinity. If i didnt temper the watee that calculator would come in clutch. I use the same site for the dosing calculator. Comes in clutch.