I have a Hovabator 1533, with a fan. The fan broke, so I changed the fan, but could only find a weaker one. 12 V instead of 15V. I am going to be hatching some Serama eggs and started it up, I had to increase the heat to 99F, from 97F, should I try to increase it again? Or leave it? The digital thermometer reads 89.9F Any advice is appreciated!