So I got a new Hanna Calcium Checker...

[RussC]

When Hanna came out with the new CA checker, I thought I'd give it a shot. I love the ease and simplicity of the Hanna Checkers. And this one is no different. Relatively simple once you get the process. But my readings are consistently high compared to my Red Sea test. Anyone experiencing this?

For example...my most recent test with the Hanna checker was 438. But with the Red Sea it was 400. The day after I did a water change the Hanna registered 459. But the day after water changes the Red Sea registers around 430. There's a consistent average in the difference, but still, I think the Hanna is on the high side. I'm more likely to believe the Red Sea results than the Hanna results.

I don't dose CA at the moment. Not really been necessary. But its next on my list. Just got my ALK dosing dialed in. So now I'm focused on CA.

 

[Randy Holmes-Farley Verified Community Expert]

The calcium checker seems to cause more issues for users than their other products.

One reason may be the freakishly extreme requirement for no calcium in the blank and in the dilution water. Even 1 ppm in it is a big problem. So be sure to use the type of water they recommend (distilled, or if you are certain it is 0 ppm TDS, maybe RO/DI).

 

[Randy Holmes-Farley Verified Community Expert]

This is what they say:

"The HI758U Marine Calcium Checker HC® uses a 100 to 1 dilution for analysis and thus requires deionized or distilled water absent of calcium to function correctly. Calcium can be found in many freshwater sources and this any amount present in the water used at the C1 phase can cause false high readings. In addition, many hobby grade reverse osmosis deionized water systems may not adequately remove calcium. This can vary based on the types of filters used, their effectiveness and frequency of replacement. We recommend using deionized water with low conductivity or pure vapor distilled water commonly found in most pharmacies."

 

[RussC]

I've been using my RO/DI water (straight from the filter). But have not checked the TDS in a while. Might be a good time to do so. Other than that, I don't have a way to really tell what's going on in my water.

Its interesting because although the readings are higher than my Red Sea test, they are consistent. However, I do prefer an accurate reading. So something is throwing off the Hanna.