where would you place the heat???

Okay...I am going to put my milks in my 30 gallon vert tank (thanks to Michelle), but I want to know where to put the heat source??? I will be using probably a 75 watt bulb and I was thinking of placing it on top of the tank, probably upon a couple two by fours, that way the light is not placed directly on the glass. I kind of want to set the tank up now and get everything right, before I get the Milks here. That way there will not be any guess work. I just didn't know if placing the light on top of the tank is best, where there is no screen, like there normally is with regular tank. Thanks for help.

Why aren't you going to use a screen?

I'm going to use a screen on the side of the tank, but it is only a small strip, since this is a vert tank. I didn't want to button the tank up entirely. I think some fresh air is good.