I am in the same situation with my 10 gallon acrylic hex tank ( 2 BETFs ). Currently a 50w infrared bulb is maintaining the heat, but I worry about the coming winter and a cold house. I am debating putting a ceramic tile between the heating pad and the tank to spread the heat evenly and minimize the chance of outgassing by the acrylic overheating. Has anybody tried this ??

Thanks in advance.