I am trying to incubate geese eggs and just got a new incubator. When I set the incubator to 33.5%, and put a "no-mercury" thermometer in, it reads "36.9". I remember reading somewhere that the non-mercury thermometers were not accurate, and it was better to use a mercury thermometer. Unfortunately, I broke mine, and I can't find a store that sells the mercury thermometers anywhere. Should I calibrate it up according to the thermometer I used? Thanks so much!