help with Hanna phosphate checker
 

so i have a hanna checker and i get different readings with the same test sample each time, now i know there is a time limit on how long the test sample will be accurate for, but im doing all the readings all within 6-9min of adding the additive. when i do my first reading i get .17 and the next two i get .10, im just wondering if any of you use a hanna checker and what is the most accurate way of using it

I always get the little package open and ready to add to the testing sample bottle for C-2 test before I start the test procedure, you have max 3 mins. to dissolve the powder for C-2 test and make sure you have a dry soft rag on hand to polish off all the finger prints on the test bottle before you put it in the checker for both C-1 & C-2 testing.
Hope this helps.

Ive always had the same problem with the hanna regardless of wiping down the glass tubes or not. I havent used it because of this for quite awhile. Interested to hear what others say.

EDIT - 3 mins max? Hm that could have played a part, I dont remember if i was that fast or not.

And for C2:, be sure to hold the button until the 3 min timer appears. My results don't vary at all, usually the same or .01. That is if I do it right... As mentioned, have to get all the powder in cleanly, and needs to mix clear. And no fingerprints. Takes a little practice to get your routine dialed. But after that, very easy, actually.

I find the challenge is to get all the regent into the sample vial. Any tips?

I cut the top off and bend the middle of the package into a v type funnel and tap it in , also makes me feel like a scientist

Cut the packet, and shape a funnel on the side. Hold the vial at an angle, not straight up and down. Then gently tap the back of the packet with your finger. And be sure the insides of the packet are opened, too, so the powder doesn't get stuck coming out.

And I think someone said it before but clean the vials off with a cloth the finger prints or salt water on the outside will give you a false high

It could be that the reagent powder isn't completely dissolved for your first reading. It takes me a few minuted to get all the floaties dissolved...

Either way, in the grand scheme of things, the difference between 0.10 and 0.17 isn't the end of the world. Or is it?

well im trying to get my water to .05, i have also read that you shouldn't have any air bubble in the vile.

3min seems to be a bit much it terms of the sample diluting, it takes at least that long to get it to dissolve