Ventilation in Breeding Tubs?

[Arconna]

How many holes is a good amount to have in a breeder tub for good ventilation? I've got 9 3/8 inch holes in the top of one of them (no animal in it yet) so was wondering if that is enough or if I need more?

Thanks.

 

[GeckoMecca]

i burn small holes with the tip of a soldering iron no more than an inch apart all the way around the top of my tubs to ensure good ventilation.