I can't figure out the Hanna Checker

[JodiI]

Ok, so I've used Salifert tests for my alk/calc/mag testing forever. For Christmas, I got some hanna checkers - alk, ph, and calcium.

My issue is with the calcium checker. I just can't figure this thing out! It seemed to work well in the beginning (December/January). It was giving me readings in line with what my levels normally are. But about 3 weeks ago it gave me a calcium reading of 510. I turned off the dosers to let things come down a bit, and alkalinity did. But calcium went to 515 (ish - I don't remember exactly). Even though I lowered the dosing, the hanna checker was reading a higher calcium reading. Highest reading I ever got with it was 570 or something outrageous. Double checked with my salifert kits, and got a reading of 340 (yes - a 200 point difference). My corals seemed to be agreeing with the salifert reading.

I switched out my RODI filters thinking that may be the cause, but no. Hanna checker still consistently reading way higher than is reasonable. Since my calcium was low, I dosed to raise it up to 420. Salifert kits registered the change - hanna checker continues reading in the 500's.

What am I doing wrong here?

I tried checking to see if my reagents were recalled, but I couldn't find them on any of the lists (to be fair, I didn't find official lists - just forum posts about which ones were recalled). And if the reagents were bad, wouldn't the checker have been giving screwy readings back in December/January as well?

I feel like its user error. But I can't find my error. Someone who is familiar with these, help me out.

 

[JuanGutz]

I had the same issue till I started using stupid expensive deionized water but hey it worked and I’m not complaining now

 

[JodiI]

Where’d you buy it? It’s actually different than the RO/DI water?

 

[JuanGutz]

Brs Hanna dionized gallon jug.

 

[Legonch]

I bought one of the hanna calcium testers, said my calcium was max, flashed a big number, red sea kit said 440, didnt try it again.....let me know how yours goes

 

[TheRealChrisBrown]

I gave up on the Calcium checker. I have the Alk that I use to double check my Salifert. I had reagents with the Hanna kit that were approaching the exp date but had not yet exceeded them, and the test results went wonky like yours did. Started out close to what I was getting with other kits, then it went up and up, I got worried when it was reading 650. Then I had Stone run a water test for me and their results were far more similar to my Salifert results. I try to be very particular about accuracy, and taking my time to do everything slow and measured. I'd say try the grocery store or Hanna water, if that does help post up on here. If it doesn't then just use the Hannas as double checkers?

 

[JodiI]

I ordered the BRS water. We'll see how it goes.

These things weren't cheap! And they're supposed to make testing easier/more accurate, so I'd be very annoyed if it ends up having to simply be the "double checker".

 

[TheRealChrisBrown]

I ordered the BRS water. We'll see how it goes.

These things weren't cheap! And they're supposed to make testing easier/more accurate, so I'd be very annoyed if it ends up having to simply be the "double checker".

I agree completely, but will you forever be pondering the accuracy.....i.e. can you actually trust it going forward? I can't/couldn't. I need to double check it against Salifert. As I said though, I've never tried the water from Hanna. So please let me know how it goes for you, restore my faith in these!

 

[Munch]

How's your Alk testing been with the Hanna? I have a dkh and PPM unit, and they both read high as compared to Salifert and Red Sea test results.

So I have 4 test kits, all read differently, very frustrating...

 

[flagg37]

I ordered the BRS water. We'll see how it goes.

These things weren't cheap! And they're supposed to make testing easier/more accurate, so I'd be very annoyed if it ends up having to simply be the "double checker".

I’ve never used the ph tester since I have a probe on the apex, but the alk Hannah tester is much quicker and equally as accurate as any other alk test kit I’ve used. The Ca Hannah tester I can’t say the same about. I’ve not had your experience of it being so far off but it’s not any easier to use than other kits. IMO the biggest advantage to the Hannah test kits is that it gives you an actual value not a color. I’ve got reefing friends that are color blind to certain colors and rely on these since they can’t rely on their own eyes.

I heard that they recently started including a special syringe for the 0.1 ml measurement. Older kits apparently didn’t have this, does yours?

 

[Munch]

I have the new syringe:

For comparison:

I have the standards test kit to go against (paperwork from factory said 103 PPM)

104 PPM which is 5.82
dkh was 5.8

good start

So I measure my water:
166 PPM which is 9.296
dkh was 9.1

close enough

So I use two different Salifert kits
Both measure 9.8 dkh

Then I use a Tropic Marin
Measures 8.5 dkh

Guess I'll stick with Hanna, but sucks the range is 8.5 to 9.8

I'm hoping I'm right around the 9 mark...

 

[TheRealChrisBrown]

Munch - I was having the same frustrations. I finally decided to have Stone Aquatics run a sample through their fancy ICP test machine. Cost me $15, which I think is their rate if you take it to the store. Anyway, at the same time I took the water sample for stone I used every test kit I had and made a sheet of the results. When I got the results back from Stone I compared my test kits to theirs and decided which were close enough and which ones were way off. I might do this once or twice a year going forward. I kind of like the confirmation.

 

[flagg37]

Munch - I was having the same frustrations. I finally decided to have Stone Aquatics run a sample through their fancy ICP test machine. Cost me $15, which I think is their rate if you take it to the store. Anyway, at the same time I took the water sample for stone I used every test kit I had and made a sheet of the results. When I got the results back from Stone I compared my test kits to theirs and decided which were close enough and which ones were way off. I might do this once or twice a year going forward. I kind of like the confirmation.

I think this kind of testing is great although it does have its limitations. It doesn’t test for alkalinity since that’s not an element. I think they do run a separate test for it though and include it with the results.

Fauna Marin used to sell a reference solution (I’m not sure they still do) with the lab tested values of what was in the bottle. I’ve used it to test my test kits to see how far off they are and then can add or subtract to get the actual value.

 

[TheRealChrisBrown]

It doesn’t test for alkalinity since that’s not an element. I think they do run a separate test for it though and include it with the results.

Correct, and I had forgotten about that. I went back and looked at my ICP results and I think I was really struggling with Calcium validity. Hanna checker read 455, ICP came back at 313. My Salifert measurement was 330.

Would a nice set of calibration fluid (a mixture at a known level) hold it's lab determined level? Or over time would it lose it's potency?