Having issue with salinity reading with apex, hanna, refratometer

[balajeek15]

lately I seem to have some issue in deciding which shows me the correct reading.

I calibrated all three with their own recommend calibration solutions.

after calibration, i dip in the 35ppt solution and all show the correct reading (34.9 in my case)

Now the issue is.
apex prob on DT shows 29.5 to 30.4 ppt
on the same DT hanna shows 34 ppt
refractometer shows near 34ppt

If i think apex prob is the issue, i dip the prob into 53ms solution it shows 34.9, i also dip in the hanna's 35ppt solution and it shows 34.9

What is happening?

 

[ariellemermaid]

That’s weird for sure. The reported issues with the Apex salinity and ORP probes is why I went with the EL version. I would trust a freshly calibrated hanna especially if it agrees with your refractometer. I can’t explain why the probe only works with calibration fluids though.

 

[Chrisv.]

That’s weird for sure. The reported issues with the Apex salinity and ORP probes is why I went with the EL version. I would trust a freshly calibrated hanna especially if it agrees with your refractometer. I can’t explain why the probe only works with calibration fluids though.

+1

 

[MNFish]

Is you apex probe new, I had a simular issue with mine when it was new.

Also did you heat up solution in tank water first and set your tc factor to 2.2 under advanced:

 

[vetteguy53081]

Apex salinity probe notorious for false readings. Its mainly due to trapping of bubbles. Pull it down in the water and turn upside down to allow bubbles to escape. As with mine, tilt it an an angle and leave it that way to allow any bubbles to escape and your reading should be good

 

[balajeek15]

Is you apex probe new, I had a simular issue with mine when it was new.

Also did you heat up solution in tank water first and set your tc factor to 2.2 under advanced:

If you are asking if the calibration solution temp, yes i did float the packet in the sump for and hour.

 

[MNFish]

If you are asking if the calibration solution temp, yes i did float the packet in the sump for and hour.

Yes I would still calibrate it with the tc set at 2.2 from how I understand it it will use your apex attached temperature probe to adjust reading accordingly one of the frustrating part about apex is I think it should sense if you have temp probe and then set that itself.

 

[balajeek15]

Apex salinity probe notorious for false readings. Its mainly due to trapping of bubbles. Pull it down in the water and turn upside down to allow bubbles to escape. As with mine, tilt it an an angle and leave it that way to allow any bubbles to escape and your reading should be good

I calibrated just before posting this thread, i took it out, cleaned it, used canned air, let it dry and then calibrated it.
i removed it and did air spray again (as you said in case of micro bubbles) and it still reads the same 30ppt

 

[balajeek15]

Yes I would still calibrate it with the tc set at 2.2 from how I understand it it will use your apex attached temperature probe to adjust reading accordingly one of the frustrating part about apex is I think it should sense if you have temp probe and then set that itself.

Sure i will try it now.

 

[balajeek15]

Sure i will try it now.

tried again, and seem like the tc is default to 2.2 anyway.

 

[balajeek15]

I had a conversation with apex support yesterday and he said apex prob is highly accurate and he had issues with hanna in the past.

The weird things is if i dip it into 53ms or 35ppt solution it shows 34.9, which is good.

Are there any other methods i could test this, like if i take a sample water to a pet store, will they check, is those worth it?

 

[vetteguy53081]

I calibrated just before posting this thread, i took it out, cleaned it, used canned air, let it dry and then calibrated it.
i removed it and did air spray again (as you said in case of micro bubbles) and it still reads the same 30ppt

Not spraying air, tilt probe upside down in the water and do not remove from water then set in the sump at an angle

 

[balajeek15]

Not spraying air, tilt probe upside down in the water and do not remove from water then set in the sump at an angle

tilt and fully submerged ?

 

[MNFish]

Also make sure in in calibration to try to get air out and tilt the bag a little....

 

[Avengerx77]

Having same issue, test my water with a hydrometer and with a Hanna tester and they fairly measure very similar at 1.023-1.024 where my APEX is showing way higher at 37,4 and keeps moving around all day. I bought a refractometer, so will test tomorrow to see where it stands

 

[MNFish]

Trust me I was cussing and swearing for a long time trying to get it right not as easy as it seems it should be..

 

[vetteguy53081]

tilt and fully submerged ?

yes

 

[MNFish]

But that tc setting helped a lot for me.

 

[balajeek15]

yes

did it, the edge is almost near the surface, and i get 43, seriously, what is this?

 

[vetteguy53081]

did it, the edge is almost near the surface, and i get 43, seriously, what is this?

Now lower it again UNDER water and place at an angle as before