Building a 150G salt water

[phish]

Hi All,
I found this msg board about 2 months ago when I decided to build a saltwater aquarium.
Since then, I've been reading and reading, and reading.... you get the point.
There are 2 issues that I have not been able to make a decision on, so I figured I ask the experts.
1) What is better, bottom or back drilled for the sump, and is back drilled, how far up from the bottom?
2) the guy at the glass shop said that I may want to bull nose the edges so that there is more surface contact for the sillicone. I noticed all tanks have flat edges. What is better bull nosed (rounded) or flat?
Thanks in advance for your advise.

 

[almarktool]

well,
first off welcome to the board glad to see u have been doing lot's of reading before jumping in ,
now your 2 questions my opion goes as so the holes well back drilled u will have to have the tank further away from a wall as far as to how far up do not have that answer , if bottom drilled u will pick up 3 inches closer to the wall
as far as bull nose i would say no you will lose surface contact just plain old flat works for me u will be installing a bulkhead fitting usually does not require any silicone at all, some people ( myself inculded ) like to put a very thin coat of it on all 4 contact points rember not to over tighten the bulkhead fitting u jus5t want to seat it usually can be done by hand i fu use a wrench and u see the gasket squeeze out past the major diameter of the fitting u are over tightneing it