Do you think this would work? Since water retains the temperature a bit better than air I thought if I threw in 6 warm water bottles it would help to keep a steadier temp. What do you guys think?
It's actually a pretty standard thing to do. It still may not avoid the on/off tendency of a non-proportional thermostat, but I'm using some incubators now that seem to keep the heat pretty steady and I think the thermostats are non-proportional. Definitely add the water bags.