I just installed my Hydrofarm thermostat. I taped the probe to the uth with aluminum tape. The thermostat is set to the max 108. The temp directly on the glass inside the tank above the uth is 99. The temp on top of the substrate above the uth is 87. The substrate is only 1/2" thick. Looking for some advice on how to raise the surface temp and balance it more with the thermostat.

Thanks!