Tricks from years of running hog tubes:
1) Once the pigs have found the pipe, 1 1/2" hole is enough, and even then they can empty it in a single night!
2) Don't fill the pipe directly, add a little corn, fill a coke or water bottle that fits in the pipe with corn and add it to the pipe without a lid, add more corn and and another bottle... repeat until tube is full. This makes it significantly harder to get all the corn out. One bottle with a lid and gravel is a good idea.
3) Once the coons and squirrels find your pipe they will chew the holes out big enough to get a their hand in. Use metal flashing with a hole in it to cover the old hole and some 3/8 or 1/2" screws to fasten it to the pipe. This also works great for covering excess holes.
4) 3-4" pipe cut in half inch slivers makes the absolute best hoops around t-posts.
5) Make sure you drive the t-post past well past the spade.
6) Hogs absolutely do not care about a couple of $10 solar spotlights from wally world mounted on t-posts just outside the radius of the tube circle. Set one to each side of your shooting lane.
7) If you add any sweet powder to your corn, you run a really high risk of having ants all around your tube the next time you fill it.
8) Don't glue on any fittings to your tube, use screws so you can easily disassemble WHEN something breaks.
9) Don't put hen scratch in your tube or the milo will grow sow tall you can't see your tube. Don't ask me how I know.
10) A 6"x8' tube lasts a good long while, but is a pain in the fanny to fill if you don't have a truck bed to stand in.
11) Mice can fit in the tiniest holes.
12) A pipe that comes loose can be a nightmare to find.
13) Do your best to keep corn in the pipe, pigs will hit it like crazy when it rewards them, but will drop it like a rock when it stops.
14) Pigs will often come back within 15 minutes of you dropping one, especially if you drop mama first.
-ww