The fans are on a dimmer switch and pull air up and blow it down the (inside) back of the unit. I've got all 3 running on a low setting.

The tub is for water.

The ceramic heater is a back up low heater. I've got a few trips that I've got to make this year where I'll be gone for a week or so and while heat kills eggs quicker than anything else I also want to protect the low side as well.

The heat tape has a back up ranco on it to shut it down completely if so some how it malfunctions and hits 91 degrees (or if the fuse blows) it completely shuts down.

The cermic heater is set at 86 degrees as it does heat up quicky. It only turns on if the unit hits 85.

I've also got a temp sensor on the whole unit thats hooked into the security system of the house to call me if the unit is below 87 or over 90.