Where do you have the thermostat probe?

[snakeynewbie]

So if I was to use one of these combos until such time as my coastal grew out of the tank i'm setting up(approx 2ft X 2ft X 1 1/2 ft) how would you set it up in the tank and where would you place an actual heat light as well?

Reptile Thermostat Thermometer + 14W Heat Mat Combo NEW | eBay

I'm going to install the mat inside a shelf about 6 inches off the ground with a hide underneath so it will provide top down heat to the hide and bottom up heat to the shelf.

I posted this pic of my tank plans the other day but as you can see I've altered the divider so that it becomes a hide on each side , I'm thinking I'll leave it open to glass so I can see in but put a lift the flap on the glass at the front of each hide for privacy