Hannah Calcium tester issues

[Romeo_Reefer]

I can’t get any consistency from the calcium checker.
It’s all over the place.
Brand new batch of Reef Crystals that’s mixed to 1.025 salinity is reading 500 on the calcium checker. The next test will show 450. I check 3 or 4 times in a row, and getting different results.
Any suggestions of what basic mistakes people make? I’m pretty handy with all the other test kits , it’s just the Hannah product that is giving me pains. Anybody having similar issues?

 

[FernBluffReef]

Hanna CA test gets a bad rap.

Make sure you are using vapor distilled water that has no MG or CA added back in to rinse your vials and for the blank. I go further and use tiration / lab grade distilled for the blank. My results are very consistent.


See below for more from Hanna

These tips below from our Aquariums manager should be helpful especially points 2 and 4.



Calcium Checker Troubleshooting Tips



1. Never rinse your cuvettes with tap water or saltwater

2. Use pure vapor distilled water from your local pharmacy at C1 phase. RODI water from home filtration units may not be suitable for this test calcium can easily permeate through your membranes.

3. Clean your cuvettes with distilled or deionized water absent of Calcium that is going to be used for C1 phase dilution.

4. Measure out 9 ml of distilled or deionized water for C1 phases

5. Make sure no excess aquarium sample saltwater is on the tip of the pipette. Only administer the saltwater that is sucked into the pipette tip.

Respectfully,



Kevin C Costa

Aquarium and Aquaculture Manager

 

[Romeo_Reefer]

Make sure you are using vapor distilled water that has no MG or CA added back in to rinse your vials and for the blank. I go further and use tiration / lab grade distilled for the blank. My results are very consistent.


See below for more from Hanna

These tips below from our Aquariums manager should be helpful especially points 2 and 4.



Calcium Checker Troubleshooting Tips



1. Never rinse your cuvettes with tap water or saltwater

2. Use pure vapor distilled water from your local pharmacy at C1 phase. RODI water from home filtration units may not be suitable for this test calcium can easily permeate through your membranes.

3. Clean your cuvettes with distilled or deionized water absent of Calcium that is going to be used for C1 phase dilution.

4. Measure out 9 ml of distilled or deionized water for C1 phases

5. Make sure no excess aquarium sample saltwater is on the tip of the pipette. Only administer the saltwater that is sucked into the pipette tip.

Respectfully,



Kevin C Costa

Aquarium and Aquaculture Manager

Nice, I see a problem already. I use RO/DI water as base. And rinse with well tap water.

I think I’ll get some actual distilled water and recheck tomorrow.

 

[SliceGolfer]

Be aware that the sampling pipette has two spring levels. Partially depressed for taking the sample, fully depressed to empty the pipette.

 

[gbroadbridge]

I can’t get any consistency from the calcium checker.
It’s all over the place.
Brand new batch of Reef Crystals that’s mixed to 1.025 salinity is reading 500 on the calcium checker. The next test will show 450. I check 3 or 4 times in a row, and getting different results.
Any suggestions of what basic mistakes people make? I’m pretty handy with all the other test kits , it’s just the Hannah product that is giving me pains. Anybody having similar issues?

The usual source of error is the DI water used to make the blank.

Any residual Ca in the blank will increase the reading.

It is often easiest to purchase a bottle of distilled or lab grade Di water.

The other common error is not using the .1ml pipette correctly. You only depress to the first stop when collecting the seawater sample, you then press to the 2nd stop to dispense into the cuvette.

Once you get a consistent method, the actual test is quite accurate and repeatable - however I found the reagent getting so ridiculously expensive I sold the Hanna and replaced with the Salifert which works just as well for hobby purposes.

 

[Romeo_Reefer]

Thanks for the feedback. Got some distilled water and getting pretty consistent results. I did start looking into the literate of the tester and it says that at 25 deg C we can expect accuracy of +/- 6%. So a total swing of about 12% is possible. So if we consider 410 ppm as a standard then : 410 x 0.12 = 49 ppm of Calcium total error.
Not sure if that's a lot compared to other testers. But seems pretty high.

Or maybe I'm just asking too much. If higher resolution is needed I should send the water out to a lab.....

 

[jabberwock]

All good advice given so far! I would add that if you are mixing it and doing water changes regularly your calcium should be pretty bullet proof. I check mine maybe once every 4 months.

 

[FernBluffReef]

Thanks for the feedback. Got some distilled water and getting pretty consistent results. I did start looking into the literate of the tester and it says that at 25 deg C we can expect accuracy of +/- 6%. So a total swing of about 12% is possible. So if we consider 410 ppm as a standard then : 410 x 0.12 = 49 ppm of Calcium total error.
Not sure if that's a lot compared to other testers. But seems pretty high.

Or maybe I'm just asking too much. If higher resolution is needed I should send the water out to a lab.....

Yeah the Hanna CA isn’t the most accurate on the market. RedSea says theirs is +/- 5ppm , but I find it extremely hard to use - I can’t discern what color is supposed to be hence it’s not accurate for me. Salfiert is said to be a bit easier to use then RedSea, but they don’t seem to say how accurate it is.

Anyway, What I generally find is the Hanna is extremely consistent when used properly. I do find when I run out of reagents and go to a new bottle there can be a shift so, bottle to bottle it can vary some. I also find I occasionally mess up and the delta then is substantial hence an obvious testing error.

Anyway, I personally just watch the trend and the absolute value doesn’t matter all that much. I test weekly and the last five weeks values are 434, 427, 427, 437, 445. That is with water changes and all, so some variation in salinity and some adjustments in dosing over time. That is close enough for me - 5 tests all within +\- 9ppm and again that includes two water changes and some dosing adjustments.

 

[BryanM]

Hanna CA tester is commonly viewed as suspect, but as you've just figured out the type of water for this test really matters quite a lot.

 

[gbroadbridge]

Not sure if that's a lot compared to other testers. But seems pretty high.

Or maybe I'm just asking too much. If higher resolution is needed I should send the water out to a lab.....

All the common tests (Hannas, Salifert, Red Sea, Nyos, etc) are all pretty similar in terms of accuracy and repeatability in my testing. Barring of course faulty reagents or reagents that have been open too long.

And they're all close enough to an ICP that nothing in the tank is really going to care.

I just use the tests to identify a trend - I measure Ca once a month and if it drifts down more than 10% a month for 2 months or longer then I would do an adjustment back to my base number (440 in the case of Ca)

 

[Rollnwthdatide]

I bought a 1000ml bottle and I keep RODI in it to use for my Ca test and to rinse. I also have a dedicated 10mL syringe for it that I can easily reproduce test. I was also rinsing with tap water and when I cut that out I noticed it was a lot better

 

[Romeo_Reefer]

All good advice given so far! I would add that if you are mixing it and doing water changes regularly your calcium should be pretty bullet proof. I check mine maybe once every 4 months.

Yea if you have soft coral, but if you have a good amount of SPS you'll reduce the Ca quantity and only bring it up a bit with a % water change. I guess once you find the consumption rate and have a good accurate doser you might not have to check as often.

 

[jabberwock]

Yea if you have soft coral, but if you have a good amount of SPS you'll reduce the Ca quantity and only bring it up a bit with a % water change. I guess once you find the consumption rate and have a good accurate doser you might not have to check as often.

How big is your tank?

 

[Romeo_Reefer]

How big is your tank?

This one is a 32 BioCube, but I've had much larger tanks in the past and testing is always hit and miss for me. So I'd figure I'll ask about other peoples experiences.

 

[jabberwock]

This one is a 32 BioCube, but I've had much larger tanks in the past and testing is always hit and miss for me. So I'd figure I'll ask about other peoples experiences.

For sure. Perspective is priceless. Better upgrade those Biocube lights for SPS.

 

[Romeo_Reefer]

For sure. Perspective is priceless. Better upgrade those Biocube lights for SPS.

Funny you should say that, I'm ordering some ReeFi this week.