CHE Set-Up?

[rachelmd_]

Hi everyone! I just got my first leopard gecko, Yoshi, a few weeks ago. He's been doing well in his new home, but with colder weather approaching, I'm thinking about switching up the heating arrangement in my room. Yoshi has a 20gal tank with a UTH, and I use a space heater to keep the air warm for him and my hedgehog. This is the first time I've had to pay my own electric bill, and I've realized that using the space heater 24/7 in my room (which is in the basement) is probably not the most cost efficient. I'm going to switch to CHEs, but want to make sure I have a proper set up. For whatever reason I can never seem to find consistent information--i.e. how many, what wattage, etc. His tank is glass with a sliding wire mesh cover & about 2.5' long. I'm thinking about starting with one CHE and a thermostat that can control two, that way I can add another CHE if necessary. What would you guys recommend for wattage? Would it depend on whether there is one or two?
Thanks for any help. Also, here's a picture of Yoshi

 

[DrCarrotTail]

I don't think you'd need anything over a 50W. I'd make sure the air temp in the tank doesn't get over 85. 90 is too warm for the air but they still need a spot on the floor that's about 90 to digest their food. As long as part of the tank is over 80 he'll be fine. The other side of the tank should be closer to 70. If it's too cold he probably just won't go there. You'll want to make sure there's a good moist hide in there and rewet it a couple of times a week. Overtank heat tends to dry out the air and can cause shedding issues if they don't have a higher humidity spot to use.