I just keep my leos in tubs. No tanks here beside for rodents. My male and female bred a while back just how the tank was. Didn't even know she was able to produce eggs since she was a "hot female". I just use 12 qt. shoe boxes with heat cable under one side. You sure can use flexwatt as long as you use some sort of dimmer or thermostat!!! That flexwatt will cook your geckos. Just keep it simple in the cage, papertowels, water bowl, a couple hides and they should breed.