Setting up a breeding tank

[EkizUCLA]

I have a question regarding what type of heater to use for my breeding tank. Since the tank will only be half filled I need a heater which is submersible and will not burn my baby's. Any help?

 

[Kiarra]

I use a Whisper submersible heater. Only cost me about $15, good for 5-15 gallon tanks. I use one in each of my two 10 gallon spawning tanks.