Yet another heating q

[invaderzimgir]

So I've got a 20 Gal long terrarium and a uth for a 20gal on the right side. Its getting cold out so I wanna increase the temp a bit. Using an overhead heat source gets it too hot. Since the tank is long the 20gal uth doesn't quite hit the whole 1/3 of the tank. Could I just switch it out for a 30-40gal uth? I figure it would help reach the 1/3 goal and add the extra heat I'm looking for.

 

[invaderzimgir]

I've also noticed that my two geckos have been spending almost all day over the uth. Ground temps are still around 90 on the uth side.

 

[invaderzimgir]

Also using paper towels as my substrate

 

[acharpenter]

Gecko's are all about belly heat - as long as there is a place in the tank somewhere where they can lay their belly - they will find it (so I would think the UTH you have would suffice just fine). The over head heat is just a bonus if it is heating something they can lay their belly on

Wouldn't hurt (and most likely they would appreciate) if you put a hide over the warmest part of the tank so that they can chill on it and still feel secure.

Please also note - the hottest part of the tank (along the bottom) should have some sort of temp meter so that it does not get so hot as to burn their bellies.....very important