Hanna UL Phosphorus HI736 Readings All Over

[Bubblebass]

I've been excited to get this meter and it arrived. My readings are all over the place. I do not own any other Hanna meters and I'm wondering if this is normal.

Here my procedure:

Fill both vials with 10ml tank water
Open regent as instructed on dotted lines
Dump in whole pack into one of the 2 vials
Shake that vial for 2 mins
Turn on Hanna, wait for it to test itself
Put the vial without regent in the Hanna when it says to
Put in the vial with the regent when it says to and hold down the button for the 3 minute timer

My numbers range from 3-9 and if I do the test immediately again with the same vials without waiting the 5 minutes the second time for the regent vial, it comes up with totally different numbers. I thought this was going to give me a solid number to go off of for GFO use, but it is nothing but frustrating. At 3, I'm thinking I need to never run GFO. At 9, I am way too high.

The instructions say to let it calibrate, add the straight tank water vial, add the regent to the same vial, hake 2 minutes and put the regent vial in the Hanna and press for the 3 minute countdown. This isn't possible, as the Hanna turns off at 2 minuted of inactivity.

So.....what am I doing wrong?

 

[Odysi]

There instructions are what you should be following 1 vial for everything. The way i do it is prep everything first. Fill the vial and make sure that it doesn't check low or high, open up the regent packet and set to the side and get a stopwatch ( i use my cell phones stopwatch). Once i start the test and get C2 reading i start my stopwatch and fill vial with regent and shake it until 1:45 on the stopwatch, clean off the vial of any water or finger prints and then put it in the reader to do the c2 3min test. Consistency is key imo with this test to get valid #'s. I always shake until 1:45 and my readings are always in range of each other.