Newbie looking for plumbing assistance

[PaulCheung]

I am working on my first DIY salt water tank. I have a 50 g tank drilled with 3 1" holes and have a 25 g tank to be converted to sump.I am thinking to use herbie overflow.

I am thinking to use flexible hose for main drain and emergecy drain and PVC for my return. For the return, I want to be able to adjust the return flow to match the overflow rate. So I think i need a type gate valve.

So far i have just bought 3 1 inch bulk heads. When i got to the hardware store, there are so many different stuffs that looks so similar. i don't what kind of plumbing stuffs i need to buy to complete my DIY project. Desparately lookomg for advices in plumbing my tank.

For starter, what is the 90 degree part the can connect the 1 inch bulk head. While my bulk head is inch, does it mean the diameter of the PVC and flexible hose is also 1 inch?

I have no experience in this thing. Any advice will be appreciated.