Thanks, Joey - appreciate the compliments.

I've been so busy, I've not had time to make the switch to the 150, but hope to do so before the New Year. My bulb is about 7 inches above the water surface. No problems with heat or splashes at this point (but remember - HQI bulbs give off UV radiation, so you need a piece of UV-protective glass between your tank and the bulb).
I have a 150 W HQI for a 20 and was told in other threads that it should not be cooled...

Disagree - unless you want to cook your tank or melt your canopy, of course!
...and it was too close to the water surface (~6-7")...
Disagree again - especially in light of the fact that you have a 20H. Post some pics of your nano - I'd love to see it!
Thanks again for your kind words... and Merry Christmas!

Floggings will continue until morale improves.