I'm sure someone knows the answer to this question. If one thermometer reads 98.5 temp (very good thermometers) just sitting on top of the eggs but the probe that is in the water wiggler reads 99.5 is that okay. What temp should I go by anyway, the one in the water wiggler or what? Sometimes the therm. sitting one the eggs may read 100.1 while the other reads 99.8 in the wiggler. Usually the difference comes from opening it to add more water to the sponges. But I was curious about this. Any insight?