Planted Tank Guru
Join Date: Jun 2004
Location: Baton Rouge, LA
Super easy to connect and dim these Lutron ECO-series ballasts, like the one I used and the one you PM'ed me about on Ebay. You use only the set of three terminals, colored white-orange-black on the left side.
Connect white to the neutral line of the AC plug. Connect black to the hot line of the AC plug. You can install a DPDT switch between the AC plug and these two terminals, if you want the fixture to have its own on/off switch; but as most people will be running off a timer, it isn't necessary.
Connect a standard wall dimmer between hot and the orange terminal. Connect a suitable resistor (as described in the original post), or even one of those little plug-in incandescent nightlights, between orange and neutral. Apart from wiring up the bulb sockets (make sure you get unbridged sockets), for which there's a handy diagram right on the ballast, you're done.
Note that turning off the dimmer won't completely turn off the ballast, only bring it down to 10%. You have to cut the power to the black terminal for complete turn off.