Last year I used an incubator for my JCP clutch but I also let my female ball maternally incubate hers. The incubator was set for 89F and the warm side of the tank my female ball was in fluctuated between 85 and 90 during the course of a day. This year I've got an incubator set up again at 89F and I'll just play it by ear with the snakes. If things are looking good, I'll let the moms maternally incubate but if anything looks amiss I'll put them into the incubator.