hanna cal checker and red sea cal

[Wick]

so i checked my calcium with the hanna checker and read 382ppm. I added 35ML of red sea calcium as it said on the back of the bottle. ( i have a 125 gal tank) i checked it later on that night and my calcium read 388ppm. can this be possible or is something off? i used RODI water to clean the tube. (covenet? forgot what they are called) thoughts?

 

[Brad Miller]

I stopped using my Hanna checker for calcium since mine was doing the same thing after using it for
1-1/2 years.

I couldn’t see buying the calibration solution, so I purchased the Red Sea test kit and after comparing the results, I’m sticking with the red same tritation method from now on.

 

[jsker]

If I may make a suggestion with your Hanna checkers, I have found to start with new tips and syringes every time I test. I found that my tests were off using the used tips after use. I seem that especially with the Ca test, having dried residue in the tips throws off testing.

I also use a 10 ml syringe to fill the cuvette with 9 ml distilled water and a pipette with 1 ml disposable tips for the Ca reagent and all other reagents.

I also use and toss a 10 ml syringe for my tank water samples each testing.

I will say that my testing is a hole lot more consistent. I will also say that I make a mistake every once in a while testing by getting distracted, but after doing the above my errors in testing or off numbers are down by over 90%

 

[Wick]

Maybe I will just was them with rodi

 

[jelee01]

My CA checker was spot on until recently when it now always reports a 380-ish number. I know that is wrong and cross-checked it to Red Sea and a salifert kit bot reading 440-ish. So dumped my checker and sticking with Red Sea titration test. Just can’t rely on the checker.

 

[ajhudson15]

the hanna cal checker is known to be off and give different results even if you test the same water four times. many including myself was able to get a little bit closer reading using distilled water instead of rodi. I would still recommend using the red sea test tho

 

[Wick]

Hmmm might switch then