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.
https://www.bulkreefsupply.com/content/post/how-to-properly-install-a-bulkhead-in-your-aquarium
ETA I try to stay closer to the smaller hole size so that there is more glass to allow the gasket to seal against.