Need some help with water chemistry

[arking_mark]

wich checkers do you rec. i have only the alk tester just purchased it so far a few tests and i like it allot, but ive heard mixed reviews on the other models. what is your take on the others?

From Hannah, I like Alk, ULR Phosphate, and Ca.

For Mag I use Auquaforest

For Nitrate I use Nyos

pH is done through a probe