The tub actually has 2 probes. I have one probe placed on the heat tape in the top slot and then the other probe placed on the heat tape in the second slot...this is a 3 slot tub.

The racks is up off the floor about 12", i have it raised by landscaping blocks and then a thick piece of plywood as the base. The thermostat is set at 99.5 which is probably hotter than the top two spots need but it heats the bottom up to close to the right temps. I just know that from the records that came with the two females when i bought them the last time they eat was October....so even though i know everyone says not to worry it has been close to 8 months so it would be great just get them to eat something. Would hides make any difference in getting them to eat???