Question about wick beds?

Hey all,

I can't find a whole lot of information about wick beds on the net for some reason. I'm trying to build my own, but I want to know more about the water reservoir.

How often do I have to clean it out? Do I ever? Where should I put the drain?

Any more information on wick beds, would be much appreciated. I really like the noocity bed, but you can't buy it. Is there anything else like it?