20 Gal. Heating Lamp Question

[SpottedBOA]

Hey Guys,
I need some help picking out a heat lamp and a bulb that will get my warm side, of my 20 Gal. Tank, to the proper temp. I am going to the pet store today, after work, so any info help. right now i have a 75 watt bulb that keeps the temp, on the warm, at 89 degrees. Do you think i should upgrade to a 100 watt bulb?

You do not need a lamp. And there should be nothing under your cool side. Id you put the UTH under the warm side keep it between 90-94 degrees and the cool should read between 72-74 degrees. there is no need for light since they do not bask.