thanks for the reply. I am taking my temperatures using a PE temp gun. As for the FW itself it is getting fairly warm to the touch. I just shot the part of the mulch that is supposed to be the hot spot and it is now in the low 90s with the dimmer turned most the way up. I am thinking it may be the substrate and might add the peat like my buddy said to make it more thermally conductive with fewer air spaces...