the tri meter are usually between 200 -300 bones.hanna also make a tri meter.personally i prefer to use differnt meters when it comes to hand held pens.if some thing happens to your ph probe like u smash the lense then the meter is fucked until u get a new one. but if u have a seperate system u can still test ec/tds/ i have a hannah red pen ph and a hannah tds.personally i think there fine for ph but i wont buy another tds meter,once i get some cash im switching to the oakton testers.