Have a few question on setting up first rack

I just purchased a 16 qt rack that is made by Reptie Basics. Do the tubs need ventilation holes? There is about a 1/16 of an inch gap between the top of the tub and rack? I'm I better off putting the thermostat probe directly on the flex watt or in a tub above the flex watt. Should the thermostat probe be positioned at the top of the rackor middle. It is an eight position rack. Any advice would greatly be appreciated.

Thanks

You only need to add holes to the tubs if the humidity in the tub is too high.

The thermostat probe should be placed directly on the flexwatt on the center shelf.