Heating

[dane]

Hi there, I need help figuring out how to heat my dart frog terrarium. The terrarium needs to maintain a temp of about 75-85 degrees. It is a wide 30 gallon terrarium with a drainage layer at the bottom with some water accumulated. I read that the exo terra rainforest heating pad might not be the best choice, one because it could crack the bottom, and two because it won't heat my terrarium enough. Any suggestions?