Drilling 55g tank hole questions

[B2Reef]

I'm looking to drill my 55g tank. I was thinking about going with a 1" bulkhead size. (I'm not up to speed on all this) but I know my tank isn't tempered via the polarizing test. I think it's recommended to have two 1" flow holes to the sump? What about the return from the sump bulkhead size??

The main tank will drain into a sump I'll be having to make out of two 10g tanks to fit under my stand.

Any sweet spot to drill the holes down from the top of the tank?

Do you agree that a 1" pvc bulkhead needs a ~1 3/4" hole drilled?

Thanks! Looking forward to getting this under way, taking my time to do it right.

 

[Reefing Madness]

http://www.bulkreefsupply.com/bulkhead-abs-thread-x-thread-1-45713f6ff2041d3fdfae927b82488db8.html
45mm drill size for 1"pvc bulkhead. But yea, its close to 1 3/4"

 

[B2Reef]

Great! Thank you, I'm now thinking on going with a Bean Animal siphon. This all seems to require two overflow boxes, an internal overflow that water flows into and out of the drilled holes and into an external overflow box and down the three siphon pipe bulkheads drilled in the bottom of the external overflow and flows into the sump, and a 3/4" return bulkhead drilled into the main tank.

Is that about the right idea right there? I'm going to be looking into making those overflow boxes if so. Acrylic or Glass, teeth or no teeth for the internal overflow, how does size/length of the boxes effect this Bean Animal drain setup? Longer better such as coast to coast? Will silicone support the external overflow box adequately? I've seen some external overflows with triangle bracing on my YouTube researching...

 

[Reefing Madness]

If you have a glass tank, you need to use glass as the material, when you silicone it in place it will bond to the glass.
There are 3 overflows, but one is used for an emergency drain.
You want to box long enough to support the amount of water flow through it, it doesn't have to be the entire length of the tank
http://www.beananimal.com/projects/silent-and-fail-safe-aquarium-overflow-system.aspx
https://www.google.com/search?q=bea...X&ved=0CCQQsARqFQoTCJHeho-ax8gCFY08iAod1DwOgg