hey there, not too educated about the PH EC testers with the calibration and all that. but will pass on any info i learn about them. i do know that i'm probably going to purchase one on ebay. i did a search for "EC PH" and it comes up with many Hanna brand testers. it is PH and EC tester in one for about 120. i read on the auction about needing some calibrating stuff to go with it, i'll end up getting whatever you need to use it and learn as i go. i do know that i need one to know my EC reading and i've been using PH strips and those are not as accurate as i want them to be. take care