I am about to spend 150 on this ph/tds/temp meature that automatically calibrates and everything. I'm running a 3 bucket circulatiting dwc. What does a few of the hyrdroponically inclined (unlike me) think? http://cgi.ebay.com/HANNA-HI-991404...ryZ43555QQssPageNameZWDVWQQrdZ1QQcmdZViewItem please. just your opinions on the abilites, upsides or downsides of this expensive ass meter. (broke cause college. lol)