In my 24x12x18 Ball python terrarium, I have a small uth zoo-med heater in the right hand corner underneath the hide box. When i place the probe on the bare glass the temp reads 103 degrees, which is way too hot. When i put a moderate amount of my coconut shaving substrate over the glass, place the probe on the substrate and then put the hide back on top, the temp reads in the mid 80's (86-85). Is there anything i could place directly on the glass and then put substrate over it? or should i just use less substrate?