is hanna salinity tester accuate?

[Krixic]

Hiya! I recently purchased a Hanna tester at my LPS upon their recommendation. I did not think anything of it but after reading a few articles about people stating that its often inaccurate, it makes me a little nervous. I mixed my salt water to 1.0025 SG based my the hanna's readings. Should I be worried? I mixed my salt in batches of 5 gal.

 

[andrewey]

If my memory serves correctly, I believe the hannah tester has a listed accuracy of 1ppt.

 

[K7BMG]

Yes they are very consistant. That said.
I have had two. Both were low by .002.
So using my Hanna your salinity would actually be at 1.027

I have accurate and calibrated means of testing my salinity.
Out of the 4 pieces of equipment three match the Hannas did not.
YMMV.
Its a good tester always always consistent but always .002 low. you just need to know where it is.

 

[Krixic]

Yes they are very consistant. That said.
I have had two. Both were low by .002.
So using my Hanna your salinity would actually be at 1.027

I have accurate and calibrated means of testing my salinity.
Out of the 4 pieces of equipment three match the Hannas did not.
YMMV.
Its a good tester always always consistent but always .002 low. you just need to know where it is.

What's the best way to get an accurate and exact reading of my saltwater?

 

[K7BMG]

Brightwell and a couple others make calibrated test solutions for various testing methods.
Cheap stuff 4 or 5 bucks from BRS or Marine depot.
The solution is good for conductivity, Refractomiters and the like.

Thats how I calibrated my Milwaukee and ATS Refractomiter.
I also have a Tropic Marin Hydrometer.
Those three are always the same.

The issue I had is my salinity went to 1.030, and livestock was not looking good. I knew my salinity was higher as the Hanna was reading 1.028, and my ATO was not keeping up.
I was worried about .028 but not panicking. I know a few people run tanks at 1.027 so....
Well when I got back in town I tested with my Milwaukee and almost had a heart attack. Thats when I learned the Hanna was wrong.

Like all of our instruments in this hobby, they need checked for accuracy, before use and trust is given.
In the end nothing was harmed in my tank but it was stupid of me not to have compaired it with others.

So just check it. Know what it does and go from there.

Yes you can do temprature compensation and stuff like that.
I dont do thoes adjustments.
My reason for this is if the unit whatever it is somehow resets itself without my knowledge then I could have a real issue with my tank.
All my instruments are always set to default paramiters.

 

[homer1475]

Been many issues with the Hanna. Basically if you get a good one, it's great. If you get a bad one, you might spends weeks figuring it out.

What I have done, is measure against my milwaukee, and properly calibrated refractometer(using 35ppt solution). With that said, you can always calibrate, then stick it back into the solution and see what it comes up to, or compare the readings to other equipment.

 

[Dub]

Being a newbie this might be a stupid question but why can’t a glass tube hydrometer be used as a standard reference? They are cheap and if kept clean wouldn’t they measure salinity through it’s density (buoyancy) measurement? Not sure how temp affects the buoyancy but my tank stays within 2 degrees and that shouldn’t have a noticeable effect.

 

[K7BMG]

It has been said the most accurate way is by use of the Hydrometer.

It just needs to be in still seawater.

 

[Krixic]

Being a newbie this might be a stupid question but why can’t a glass tube hydrometer be used as a standard reference? They are cheap and if kept clean wouldn’t they measure salinity through it’s density (buoyancy) measurement? Not sure how temp affects the buoyancy but my tank stays within 2 degrees and that shouldn’t have a noticeable effect.

From what I understand, hydrometer are not all super reliable. They are good for a general reference but you want more exact numbers if you are going to keep finicky coral and fish. I could be wrong as I'm a beginner as well. This is just what I've heard.

 

[Krixic]

It has been said the most accurate way is by use of the Hydrometer.

It just needs to be in still seawater.

What do you mean by still sea water?

 

[Dub]

It has been said the most accurate way is by use of the Hydrometer.

It just needs to be in still seawater.

I just dip some water with a tall tube and replace it after the reading.

 

[vetteguy53081]

I Myself question accuracy of the hanna unit as it failed me at least twice with false reading

 

[Dub]

From what I understand, hydrometer are not all super reliable. They are good for a general reference but you want more exact numbers if you are going to keep finicky coral and fish. I could be wrong as I'm a beginner as well. This is just what I've heard.

From my limited knowledge of engineering It measures density and if the glass is clean and no air bubbles clinging to the tube and you don’t submerge the entire tube It should be very accurate. I use a tall slender glass tube to dip water out of the aquarium so there is no water movement during the test. Quick and easy and no variables to worry about.

 

[K7BMG]

What do you mean by still sea water?

Still as in no movement, flow or otherwise.

 

[Krixic]

I Myself question accuracy of the hanna unit as it failed me at least twice with false reading

Yikes, what measurement method do you use?

 

[vetteguy53081]

Yikes, what measurement method do you use?

Was PPT. I switched to sG reading

 

[Billldg]

I love the Hanna checkers, but no so much with the the Hanna Salinity checker. I have had it go out of calibration within a week. Talked with Hanna at Macna 2019 and found out that you have to keep the probe hydrated between tests, aka, add their solution in the cap to keep it hydrated for it to stay accurate. I have had it say 1.026 and I used the water, and come to find out it was 1.030. I switched back to refractometer and my salinity checker stays in the case. I love all their other checkers, but not this one.

 

[Krixic]

Was PPT. I switched to sG reading

So measuring methods can impact results? Thats so wierd. Would you know why this is?

 

[Krixic]

I love the Hanna checkers, but no so much with the the Hanna Salinity checker. I have had it go out of calibration within a week. Talked with Hanna at Macna 2019 and found out that you have to keep the probe hydrated between tests, aka, add their solution in the cap to keep it hydrated for it to stay accurate. I have had it say 1.026 and I used the water, and come to find out it was 1.030. I switched back to refractometer and my salinity checker stays in the case. I love all their other checkers, but not this one.

Dang that bites, I wish I could return it. Could have been worse I guess. What refractometers do you recommend? Ill compare it with my Hanna and see what the discrepency is if any (lets hope not :))

 

[Billldg]

Dang that bites, I wish I could return it. Could have been worse I guess. What refractometers do you recommend? Ill compare it with my Hanna and see what the discrepency is if any (lets hope not :))

I use a simple BRS refractometer.