Hole saw and buckhead size question

[cobray]

I'm going to drill a tank for the first time. I've watched a lot of videos, etc. so I have a pretty good idea of how I'll approach it.
I need to decide what size hole saw to buy and what size bulkheads will fit the hole I drill.
I'm hoping to go with 1 inch pvc plumbing.

What size saw should I get?

Thanks!

 

[Gtinnel]

There is a chart on BRS site that gives the size ranges for different bulkheads.

How To Select and Properly Install Aquarium Bulkheads

Bulkheads allow you to transfer water from one side of an aquarium to the other and allow for traditional PVC plumbing to be connected. In most aquariums, bulkheads are used for drain and return pipes on your display tank but can be used for many other things too. Some tanks come pre-drilled for...

www.bulkreefsupply.com

ETA I try to stay closer to the smaller hole size so that there is more glass to allow the gasket to seal against.