I used a mini halogen in my 20 gallon tank with my baby dragon. I don't think it would work well for a larger tank because the output of heat was pretty narrow. It worked fine in the small tank, but now that I have moved him to his 4 x 2 x 2, I have switched to a regular size halogen so he will have a larger area for basking. It also seemed like after using the mini halogen for a month or so, it wasn't putting out the heat like it was at first either. My beardie seemed to move closer to the bulb, im assuming to try and get warmer. I was happy to get his new viv finished.
I hope this helps you.
