I have a hanna combo that is real good except the ph probe goes once a year and it's like 80 bucks for a new probe. The ppm's have not failed in 5 years. Calibration is a little tricky but not too bad and holds it nice.

Here lately we use the ph600 milwalkie. Milwalkie's are some of the best. From cheap to real exspensive. Only problem with the cheap one is my bro drops them in the water and doesn't know how to dry them out. Ruined. But that's why I get the cheap ones. LOL.