Questions - Need some input

I have a standard 75g non drilled but thinking on drilling. My question is if i want to use 1" pvc, do i need use 1" bulkheads and what size glass drill bit do i use. As well how far from the black trim do i drill hole from?

I just got a blue hippo tang last thursday. He still is not eating anything i have givin to him. I have tried rods food flakes nori going to try some brine shrimp tonight. But i need help to get him to eat i don't want to lose him. Thx.