i use the ranco for my rack and herpstat for the incubator. My ranco to keep temps in the 89-91 range is set at 92 on the ranco. check temps daily and there always on. will switch to the herpstat on the rack as soon as i get around to ordering another one. I have no problems with the ranco but i like the herpstat a lot better. Plus its always good to have a back up in case anything happens. With 25 snakes id rather be safe then sorry