I'm wondering if I should install a ceramic heater in my beardies tank for the night. It's getting quite cold which I don't think is good for her, around 7°c or lower. I was thinking a 25watt one, don't know if I'll need a thermostat, we have bought two in the past and have never been able to set them up.
Things you should consider :
1) enclose the viv (solid timber plank covering lid) <--- will trap any heat created by the basking light during the day in the tank and promote a very stable thermal gradient and microclimate in the tank.
( open topped , mesh topped vivs are hopelessly inefficient thermally , see this : viewtopic.php?f=34&t=236332&p=1816614#p1816614