Question to all the tub users.

In all my tubs, I have 3-6 rows of holes (1/8" or so, the size of the soldering iron) in the front depending on the tub size, and a single row of holes down the long sides of the tubs. All the holes are about an inch apart.

The tubs average high 60's, low 70's in humidity so I like as much ventilation as possible. My house alone averages 40-45%.

Something to try, put your substrate of choice in, arrange everying how it will be once the snake is in and then check the humidity. If it's too high, add a hole or two. Wait two hours, check again, if it's still too high add another hole. Repeat until it's where you need it, and then you know what you need for that size tub.

One of my racks has a bunch of holes and the other has none. I use the same substrate, they're in the same room, and end up with very similar humidity readings. It depends on the rack, the tubs, the substrate, the location in the home, where the home is in the country... a lot of things go into influencing the readings. ONly way to figure out how many holes you're going to need is to get a reading and start making holes.

Enough :P

You have to play with it a little. I start out with less holes and add more if I see a lot of moisture build up on the sides of the tub. If you put too many you can cover them up with tape, plastic, etc.

I have 8 holes in all my tubs, 4 on each end. If its too much, which most of the times its not, I just do what SlitherinSisters said...just cover holes with tape.