It wasn't an incubator, it was just a test to see how it would do in certain conditions, I usually show it to people who believe that an aquarium or rubbermaid tub isn't sufficiently insulated to be an incubator, or for people who are wanting to build one, but are skeptical.
I have never made an aquarium incubator, but a fan is needed to regulate the heat throughout the incubator. I have a few pictures of a rubbermaid tub with a light fixture, attached to a water heater thermostat, and a small metal desk fan.