Hannah checker test kits

[pisces 12]

So i have a problem with the Hanna checker ULR phosphate and my ALK test kits the first test on the ULR Phosphate reads 0.13 and the second reads 0.03 which i know is probably right since i just dose Phosphate RX the day before, ALK reads 8.1 on three separate test and my salifert test kit it reads 9.3 big difference , all test were all done correctly and i even celebrated both PHOS AND ALK , so im at a crossroads wether to chuck the Hanna checker and go with salifert a cross the board

 

[bertoni]

It's hard to be sure which is more accurate, but I might try seeing if a local fish store could run a couple of tests before deciding. The Salifert and Hanna alkalinity kits generally get good reviews, and I'd hope they'd be closer. Any kit or set of reagents can fail over time, though. How old are the Salifert kits?

 

[kruler]

I have a similar issue with an almost new Hanna ULR Phosphate checker. Consistently reads above .13 but same water tested at LFS is .003. Seems weird to have to go out and spend money on test kits to check my expensive Hanna checker.