Substrate Heater

[mwood2]

Well I am setting up my next tank and I am looking to try out a substrate heater. Its going to be a planted tank with a very thin layer of florite below a layer of sand. This isnt my first time using sand but I am looking to use a substrate heater to prevent problems. Which are the best ones?

 

[Curiosity101]

What problems are you trying to prevent by using a substrate heater? I don't think I know of anyone using one... and I know ALOT of people using sand.