PO4 test kits - Hanna VS Salifert

[Ryanerickson]

I also did it both ways last night I got a ready of 12 the instruction way and 5 your way one thing I find doing this your way is I have much more time to Polish up the vial and confirm all micro bubbles are gone, possibly this is why I get the lower reading who knows.

[tang daddy]

Ryan is there still powder in your vial after the short time you mix?
I usually premix my vials then do the test. But maybe I'll try the other method this time. Reason I premix before starting the test is because the powder takes time to melt and mix in. Perhaps my water is not warm enough. I find that emptying the packet into the vial and mixing it 10times with a rolling motion leaves a bunch of unmixed powder at the bottom.