Just to echo the above advice really. Ceramic heating is by far the best way of heating a wooden viv (IMO OFC
). It allows you to heat the ambient air temperature and also provide less, but necessary, heat to the cool end. It overcomes many of the drawbacks of heatmats. I would ditch the mat completely and use the ceramic setup running on your pulse-proportional thermostat.
Many of the dials on thermostats are vague at best. The mest method for setting the temperature is to use the dial in conjunction with a digital thermometer inside the viv. Place the probe for the thermometer on the floor directly under the ceramic bulb. Wait for a while until the temperature stabilises, and then depending on the reading, nudge the thermostat dial "up a bit, down a bit" until the thermometer reads the desired temperature.