Doobie, lots of good choices out there for a pH meter, TDS/EC,... I like TDS because it's an extrapolation of EC into ppm's, a more "user friendly' measurement,.. Here in the States, it's not a problem, but just an FYI, EC is universal measurement, but TDS isn't... pop in
here to get more info if you like! for US, 1.0EC = 500ppm
.... HM is a good company too, but no matter what you get, be sure get the storage solution, and 7.0 & 4.0 calibration solutions,... Have Di/RO water on hand, better to control pH unless your tap is soft/low ppm.... gotta rinse the unit clean with RO/Di water after
every use (all my lab experience makes me anal-
-- for good reason though!)...... I'd get an Accurate 8 soil pH probe too, nothing beats direct in-pot measurement, and in Autopots, collecting run-off is FUBAR!
..... are you running coco or soilless, or true soil?
... looks like you may have to order the clay pellets, or the big chunk pumice-type stuff,....