nswhite

I'm trying to calibrate my NO3 and PO4 test kits. I did have a question about how many ml to add. The chart from PPS How to test nitrates and phosphates says.

To test NO3 using the following Standard Solution mix
2ml in 10l= 5 ppm
4ml in 10l= 10 ppm
8ml in 10l= 20 ppm
12ml in 10l=30 ppm
16ml in 10l=40ppm
20ml in 10l=50 ppm

My question is you start out by putting in 2ml into the 10 liters of water then test,now after that you then move on to 4ml but here's where my question is now do I add only 2ml since I already put in 2ml on the previous step? so the 2ml from the first test and now 2ml more for the second test would equal 4ml. Or do I add 4ml on top of the 2ml I already added? Hope this makes sense to somebody.

nswhite

Can somebody help me with this????

dennis

I am not exactly familiar with Edward's directions but if adding 2ml of the stock solution to 10 liters of water provides 5ppm, then an additional 2ml would add another 5ppm for a total of 10ppm. You'll notice that after the first two tests you add 4ml more each time, which is 10ppm increase each time.

As I said, I am not very familiar with PPS but based on your post that is what is happening.

I don't understand the 10 to 1 part of your post though......

OK, I went and looked up the article. It reads: 2ml in 10 l, that is an L not a 1(one). So that makes sense what I said earlier.

nswhite

Ok thanks dennis thats what I needed to know.

Edward

Hi
Dennis is right. 8 ml of SS-Standard Solution in 10 liters makes 20 ppm NO3.


Thank you
Edward

nswhite

Ok thanks again everybody. So I calibrated my test kits the first one was an API NO3 kit and it tested perfect. The colors matched up perfectly. Next I calibrated my Hagen PO4 kit and it also come out perfect. Thanks again for the help.

Edward