Hanna checkers good or no good?

[Rick Mathew]

I use the Alk...Ca...Phosphorous (converted to PO4) and Nitrite Checkers. With good lab testing methodology I have gotten very repeatable and reproducible results. It took a little work to get the test procedures nailed down but my gage R&R error is now less than 10% of the allowable limits of the test being performed. (Ex. Ca...350-450...Range 100...Gage error about 9) Therefore my test precision is good. I check the accuracy on a quarterly basis by comparing my results to outside testing results and for the most part my results are withing +- 10% of their results (Exception is PO4...Have some work to do here to get better accuracy, but the precision is good...always testing a bit high)

Just a note on the Hanna Calcium Checker. I have had very good success with this checker and have been using it for over 2 years. I made three changes that brought my Gage repeatability and reproducibility to less than 10% of the target range (100...350-450)

1) Purchased .3mL syringe...very accurate...You can find these from multiple suppliers

2) Use Hanna Deionized water (HI70436) and not my RODI water which has a small amount of calcium in it and is variable from batch to batch.

With the dilution ratio being so high and the water sample amount being so small these two changes took my R&R (repeatability and reproducibility) from between 30-40% (not good! almost random results) to less than 10% a very acceptable range for this test. My results have been validated by external testing sources so I feel confident in the measurement.

3) After the test is complete I rinse the vial and cap with the Hanna deionized water then fill the vial to the top with this water and store it this way until next use. Then on the next use I empty the vial do a quick rinse with the deionized water and proceed with the test.

IMO with good laboratory practices these checkers are great tools and do not rely on color change interpretation to make the measurement which in itself is a variable

 

[RobBaglieri]

Not knowing how you test and your regiment, its hard to give you a hard and fast answer. But here's what I would recommend.

• Get the Alk tester - its easy, fast and reliable.
• Get the Calcium tester if 1.) you are meticulous in your ability to follow directions, 2.) have a steady hand and 3.)dont "fudge" any of the measurements. I find the calcium checker perfectly accurate, but many people find it difficult because of the multiple reagents and small sample size (0.1mL) of water added to the vial. Then again, Im a chemist, so I do this stuff at work all the time The easiest calcium test out there is the Salifert test. I get accurate results when compared between Red sea, Salifert and Hannah.

I bought a bag of 1.0 mL pipetts on amazon. They can measure 0.1 mL very accurately.

 

[madweazl]

No sooner then I say my calcium checker has been fine, it spits out something crazy (490+). Tested twice with results of 495 and 497. Checked with the Salifert and got 455. Going to check the RODI and try again. I havent dosed anything or done a water change so it should be 455 at most.

Edit: New batch of RODI still came out to 484.

Edit 2: Reagents (A and B) expiration is 06/19.

 

[mcarroll]

About the dissenting opinions....

There's always room for defects and out of date reagents....happens to me with my Salifert kits often enough....mostly on the tests I don't do very often. Count on it, these things will happen with any test.

Unless you find that your unit or reagents are defective, however, there's nothing wrong with the Calcium Checker.

Perhaps the procedure could be simpler, or more similar to the kits we're used to. But in fact, I think if you/we weren't already acclimated to drip-tests and their idiosyncrasies, I doubt you'd even think twice about the procedure for the Calcium Checker...if you pay attention and do it right, paying attention to this kit's idiosyncrasies (this is more like a piece of lab equipment than a simple test kit), it works.

(I never used anything but RODI from a well-maintained RODI system, BTW.)

 

[Bruce Burnett]

I have the Hanna alkalinity, calcium and phosphate testers and originally I had trouble getting accurate results but today not I would not go without. If I get what I think are erroneous reading I will redo and if necessary use my Red Sea to double check.

 

[david p.]

BRS have a video on the test kits.

 

[mwilk19]

For the heck of it this morning I ran the calcium test with the Hanna checker being very careful with the measurements. I used my own RO\DI water. My water tested at 418. I ran the Calcium test with the Red Sea test kit and got 420 so go figure.

 

[mwilk19]

Well, I contacted Hanna and they sent me the syringe and deionized water. I have new reagents. I ran the tests multiple times and got readings 100 ppm higher than what they should be. I tested against the Red Sea calcium test kit and the Elos kit.

 

[mwilk19]

Update: I sent a water sample into Triton for an ICP test two weeks ago. I tested all major parameters at that time to see how my tests compared. I tested calcium with the Red Sea test kit and got a reading of 395 ppm. I tested with my Hanna calcium checker and got a reading of 466. The Triton test was 486 ppm. It looks like the Hanna checker was much more accurate than I thought.

 

[Rick Mathew]

Update: I sent a water sample into Triton for an ICP test two weeks ago. I tested all major parameters at that time to see how my tests compared. I tested calcium with the Red Sea test kit and got a reading of 395 ppm. I tested with my Hanna calcium checker and got a reading of 466. The Triton test was 486 ppm. It looks like the Hanna checker was much more accurate than I thought.

That has been my experience also...it takes a little care and the right tools but my results have been spot on according to outside test results