Hanna checkers

[freeze]

I have them as well, have found the Hanna's way more consistent and easier. Red seas are okay but don't get the best or most consistent readings. They gave me a good ball park but nothing definate.

[The Guy]

I have the Hanna phos checker and find it good, the only thing is the little paks of regent . They are a PITA, wish they would come up with a liquid regent so you could just use a drop or 2 instead of trying to get all that powder into the test bottle with out spilling part of it.
I use Salifert testers for the alk, cal & mag.

[mrhasan]

For alk, the accuracy of the device keeps me away (+/- 5% of the reading between 4.2 to 14). I keep my alk around 8 so that translates to an inaccuracy of up to +/- 0.4dkh. For a $60 machine, that's unacceptable to me.

Don't have any experience with Ca.

For PO4, I don't love it but I can't hate it either because of all the "guess the shade of green" test, hanna atleast get it "right" to some extend and I don't have to play the shades of green game.

[Mark 972]

Bad experience with the Hanna calcium checker! It registered 600 so we stopped dosing. After some advice from other people in the hobby, we purchased 2 other test kits - Elos and Salifert. Tested and compared and calcium results - Hanna checker was out of this world and other 2 kits matched at 420.