Why my hanna calcium test was off

[Ippyroy]

I was testing my calcium this morning when I realized my mistake. I rinsing and refilling the cuvette in the DT when I realized what I was doing. Now I know why my calcium has been so high. It is actually at a nice 422 not 500 plus. Such a simple and easy mistake. Don't rinse the cuvette out with tank water.

 

[Chuk]

I was testing my calcium this morning when I realized my mistake. I rinsing and refilling the cuvette in the DT when I realized what I was doing. Now I know why my calcium has been so high. It is actually at a nice 422 not 500 plus. Such a simple and easy mistake. Don't rinse the cuvette out with tank water.

This is typically not true. However, because the sample volume for the Hanna ca test is 0.1 ml I agree. Any residual in the vial can throw off the results. Heck 1 drop of water is about 0.05 ml which would throw off the results by up to 50%.
I’m not a fan of this test because of the low sample volume. I’m a bit ticked I wasted money on it 5 years ago and it sits on the shelf collecting dust.

 

[Ippyroy]

Its habit to rinse all testing vials and droppers in the water being tested. As I was rinsing it out it dawned on me. I am happy with it. It is the only test kit that you shouldn't do that in. .1 is a tiny amount.

 

[h2so4hurts]

I only rinse with DI. If I use RO it's +20-30.

 

[Ippyroy]

I only rinse with DI. If I use RO it's +20-30.

I realized this morning that sometimes I used RODI and sometimes tank water. My readings were all over the place. Now I know what I was doing wrong so the problem has been solved. It's amazing how easy it is to make such simple mistakes. I guess I will be replacing the water in my RODI jar more often now too.