Oh, and no, the meters are not cheap. You can get a cheap one for 25-30, but then you will need calabration solution too.
It sounds like a worthwhile investment though. I am a data driven type of person. I can't do it right now but hopefully soon I will be able to get one.
Well a good investment would be a Bluelab. It's honestly the last meter you will ever buy. http://www.ebay.com/itm/BlueLab-Combo-Meter-pH-EC-TDS-PPM-Temp-CF-Blue-Lab-nutrient-electrode-/251259414088?pt=US_Hydroponics&hash=item3a803a6648 Then every few years you'll replace the pH probe. http://www.ebay.com/itm/Bluelab-pH-Probe-Replacement-meter-combo-guardian-calibration-blue-lab-/251261769258?pt=US_Hydroponics&hash=item3a805e562a
OOOOO that looks like a fun toy. I can see myself testing everything from plain tap water, to water after it's heated by the water heater too. I love stuff like this lol
Well in my opinion, if you're going to grow cannabis, you're going to need a tds & pH meter. If you're going to need one of each, might as well get a combo meter where you can replace the pH probe. The tds (ppm) probe never goes bad and you'll only need a pH probe every few years. The cheap ones are not water tight and I guarantee you'll drop it in the soup, I went through 3 or 4 before I realized that I'm not saving money buying the cheap ones. That was like 5yrs. ago and I've yet had to replace my pH probe, it will still calabrate every time.
This is exactly why modifying cars got so expensive for me. "Well I got these camshafts now, While I'm in there I need to go ahead and get some titanium valve springs and retainers. Oh I should get the HKS rocker arm stoppers too." When I get into something I enjoy I tend to go overboard. haha and I tend to gather as much data as I can at all steps. My buddy was giving me crap because I charted out my lighting and setup. But whatever I have fun with stuff like this. Thanks for the help. I'm glad I stumbled across this site the other day.