Hanna Phosphate Checker, small experiment page 2

I do the exact same thing.

 

I've been pouring the powder onto a small piece of paper, then rotating the paper into a funnel. Seems to get all of the powder in this way. I have a very small plastic funnel that I tried, but some of the powder was left behind on the funnel.

 

So a little update on the checker that I think may help some others, specifically reefbruh based on your post above.

After realizing I did not follow the directions and hold the button to allow for the countdown I decided to retest and my phosphate reading went from .03 to .13. So a week later it was time to retest again and I made a paper funnel to make it easier to get ALL the powder. I then performed the test twice. The first time I filled both the vials with the 10ml and mixed the powder into C2 allowing it to dissolve for a full 2 minutes without worry of the checker turning off. I then used the first vial as C1 to calibrate and immediately following used the mixed one as C2 and got a reading of .06. To confirm this reading I then took the original C1, re calibrated the checker, and performed the test per instructions and recieved a reading of 0.00. Thinking it could be tainted from the fact it sat without powder for 10+minutes I re performed the test a third time using the same vial for C1 and C2 as per instructions and once again got a reading of 0.00.

It is not much of a difference but for those who really pay close attention to numbers and trends it is enough to make you scratch you head. My only guess would be that the very slight differences in the glass of the vials is enough to cause a slightly inaccurate measurement. Obviously to our eyes they look the same but to such a sensitive instrument it could tell the difference hence the need to re calibrate with each test we perform. Also, I can only assume the difference between someone vial A and vial B might not be the same as someone elses vial A and vial B.

 

If you want accuracy but don't want to pay the $ check out Hanna ULR Phosphorous Checker. It's going to be your best bet. This checker reads ppb vs ppm, there's a simple math equation you need to do but man oh man the results are consistent and accurate.

 

I might have to purchase that one as well it would be nice to test them against each other

 

Here is a handy online conversion tool for converting ppb to ppm..


ppb to ppm conversion | number conversion

 

Th conversion is a little more advanced, here's the simple equation.


PPMx3.066/1000

Example:
7x3.066/1000 = .021ppm

I made a simple excel spreadsheet to use on my phone.