Rob -
Another great show. Lighting is a very complex topic, and you are doing a good job of putting it into layman's terms.
Some suggestions: (you did ask!)
A discussion on color temps for the various bulbs and how they change the apparent color of your tank (doesn't have to be technical, more an observation)
Cost vs. watts/output vs. lifespan of the various bulb technologies. I realize that this would take a bit of time, and there are a trememndous amount of variables, but I think it would be interesting. If you are too busy, I would be happy to volunteer my time to do the research. I am downsizing my 240 to a 180, and I am planning on switching from
PCs to
MHs at the same time, but I have recently switched to
T5s on my 46 and really like them. I'm trying to weigh all the factors involved, included the cost of a chiller if I switch to
MH, and the cost of electricity as well. Anyway, I think it might be useful information. Let me know what you think.