We are planning to use sand in our coop with these nesting pads in the nesting boxes https://www.amazon.com/Precision-Pe..._rd_t=40701&psc=1&refRID=F4WQB9509VYKFC6RTN81 The run is being built on just plain dirt. Should we look into a deep litter type of substrate for the run? If so, what's recommended? It will be about 20'x10'. Thanks!