distance from edge for bottom drilling?

[scumonkey]

When drilling holes in the bottom of a tank, should they be spaced
from the edge- the same distance as the diameter of the hole?
Say the hole is 1.5 inches- should it be drilled 1.5 inches from the edge?
I need two holes- does this formula apply to the holes as well?
Second hole 1 inch so...one inch from edge and 1 inch from other hole?
I don't want to compromise the glass!

 

[hangles]

Yes always stay at least the diameter of the hole from the edge of the glass or another hole. i would keep the two holes as far apart as possible and still fit in with what you are doing.