Hannah Checker - too much calcium?

[TonapahNorth]

Im not sure what’s happening. I haven’t checked calcium in quite a while. Over 90 days. I figured I should pay attention since I have some new corals coming out of QT in about a week.

I tested last week and the Hannah checker flashed 600 which means the CA level was over the testing limit. I tested 4 times since then. And each test is flashing over the testing limit.

Mag is 1410
Alk is 7.9 dKH
CA is reading over 600
Ph is 8.2 average

LPS corals that are in the tank are great and growing really well. I have no SPS in the tank at the moment.

I’m at a loss. I don’t dose 2 part or Kalkwasser like I do in other tanks. But I run zeovit which is new for me.

Any thoughts?

 

[Randy Holmes-Farley Verified Community Expert]

Try the checker on some new salt water.

 

[TonapahNorth]

I’ll check it tomorrow and report.

 

[tgionet]

Make sure to clean the cuvettes with RO/DI before using the checker. Any residual calcium can throw it off since you’re only adding .1 ml of sample

 

[TonapahNorth]

Thanks. I’ll give it a thorough rinsing .. again.

 

[TonapahNorth]

Retested from my FSW tank, which fills from a RODI reservoir. I manually mix in the salt, which is HW Reefer salt.
The FSW is 1.025-1.026 and I keep it at around 78 F. (I'm not sure why I heat it). Anyway, the water in the FSW reservoir also reads over 600 on the Hannah checker.

TDS meters on the 6 stage BRS RO/DI unit read 69 on line 1, 42 on line 2, and 29 on line 3. It was time to replace filters anyway. They will be delivered tomorrow probably. Will this affect CA levels?

I will next try another test kit and get back to you.

Thoughts? Is too much CA a bad thing? I'm not particularly seeing any precip ... yet

 

[tgionet]

Test with a different test kit. The Ca Hanna checker is way too prone to human error to be useful imo.

 

[rkpetersen]

I like (not love) the Hanna calcium checker, it gives me consistent and accurate results. The trickiest part by far is getting an exact 0.10 ml sample into the cuvette; you have to take great care to measure the exact right amount including any partial drop that may be clinging to the end of the syringe. Also, for all the Hanna checkers that use solid reagents, it is very helpful to buy some small plastic perfume funnels and pour the reagent into the cuvette through these; with the small mouths on the Hanna cuvettes, it's otherwise very easy to spill some reagent and maybe not even notice it.

In this case, though, OP's checker isn't working properly. Make sure your technique is correct, replace the battery, and if it still doesn't work, get a new one or try something else.

And it never hurts to have multiple different test kits on hand. For calcium, I'd try Salifert, Elos or Giesemann. First thing I do when I get an unexpected reading is repeat the test. Second thing if the result persists is repeat the test with another kit. Third thing if the result persists is swear and start acting on it after sending a sample to Triton or ATI for confirmation.

Also - Isn't your RODI TDS rather high? I get anxious when mine is anything but 0.

 

[TonapahNorth]

Yes my TDS is high. I ordered replacements last week. I just haven’t got them yet.

I have repeated the test paying careful attention to procedure. I even got clean cuvettes each time and paid careful attention to the micropippette usage. I’m trying to find a new test kit ... I know I’ve got one around here somewhere.

 

[rkpetersen]

I'd run your Hanna calcium checker on the RODI water and see what you get. Not even sure the checker works properly with a fresh water sample, but it might given the small sample size, and the results could be interesting if non-zero.

 

[TonapahNorth]

Well, I can tell you that I repeated tests with Red Sea Calcium Reef Foundation Pro kit.

I tested my new salt water tank (NSW) twice and display water twice.

Test 1 of NSW - 440
Test 2 of NSW - 440
Test 1 of display - 410
Test 2 of display - 415

I’m very disappointed in the Hannah Checker CA. I’m going to figure out what’s happening there.

 

[rkpetersen]

Well there you go, something's wrong with it. One last thing I'd do is have a friend do the test with my Checker on their own tank.

FWIW, mine's worked flawlessly from day one. As have the other 4 Hanna checkers in my reef lab.

I probably sound like a Hanna sales rep. But I think their checkers have some real advantages over standard kits. The electronic colorimetric sensor can detect small differences with far greater sensitivity that the human eye, especially given the limited gradations and color accuracy found on most test kit color charts. They also zero with a blank as the first step in the test, very important, similar in purpose as putting a second water sample in a separate tube as seen with most tests, but again, far more precise.

There are some big problems with the Hanna checkers, though, and I can see why they might frustrate many hobbyists. At times, they almost feel like they've been designed for you to fail, thereby having to do the test over again and use more reagent. (And they are quite stingy with those reagents, as well.) The reagent packets can be tricky to open and pour in the small-mouthed cuvettes, and the internal timers are too short, too easy to press incorrectly, and too quickly expire unless you're moving right along and also paying fairly close attention. Once you get the hang of it, it's not hard to get accurate reproducible results, but many probably say 'nope' before that point.

If Hanna were able to create Checkers for NO3, Mg, and K, I'd definitely try them out. (Also Sr & I)

 

[TonapahNorth]

I have Hannah’s CA, Alk dkh, Nitrite, PO4, and Salinity testers. I’ve never had trouble with any of them except CA. Clearly I was doing something wrong. I just haven’t figured it out yet.

I’m gonna have to keep on top of parameters a little more so I need to get on top of the CA, Mg, Alk testing.

Thanks for all the help everyone.

 

[ksfulk]

One way to see if the checker itself is off is to pick up a set of calibration standards from Hannah and see what number your checker comes back with. If the calibration is off, then it will consistently show high/low numbers, regardless of your technique.

https://www.bulkreefsupply.com/hi758-11-calcium-standards-for-hi758-hanna-checker-marine-water.html

 

[TonapahNorth]

Thank you. I’ll do that.

 

[Rickyrooz]

Unfortunately to make the kit accurate you will need for fork up another $20. I have the old kit and like you my readings were always close to 600 ppm. The newer Hanna Calcium checker includes the new pipette to add exactly 100 u/L of sample tank water.
http://hannainst.com/graduated-pipette-100-l-hi731339p.html