This post from last year motivated me to try them out.
Planning to use the one I have on a new 10gal. Never quite got around to wiring mine up. Thanks for motivating me, folks.
Nice link, that takes the scary out of wiring up the plug. If you order the sans plug model, these things are the cheapest lighting option hands down, as the 10w costs around 10 bucks, you cant even buy a clamp on light with CFL bulb for that.
That is a 17" deep tank, and standard aquarium glass will block about 15% of light allegedly. If you have a deeper tank, I would buy the highest wattage you can afford, and hang it high/shade it out as needed-although I don't think you would need more than the 50W in a planted tank.
From looking at that tank though, that is not low light, at least medium in my eye-but I suppose a par meter is better than the eye test.