WindsorAquatic-Bulkhead holes compromising strength of glass?

[mcox]

Planning on drilling 1/2" glass with 5 holes near the top back of tank(72"L x 30" W x 30" H approx. 280 gallon-will be fully braced at the top). Hole size would be 2 3/8" each. I am wondering if this would compromise the strength of the glass enough to cause it to break. Also, if I put 2 additional holes about half way down the back panel 1/3rd in from each side (same size holes as those at the top), would this compromise glass integrity? I am just trying to leave options open for enough future flow/closed loops if I decide to go that route. Windsor Aquatic, if you are out there, I would appreciate your take on it as well

 

[windsor-aquatic]

I don't see any problems if you are sensible about the spacing of the holes, we frequently drill that many and more for closed loops. weirs, etc. You mention "for future flow/closed loops"; if some of these holes are not going to be used yet, presumably they will be blanked off. Have you considered the difficulty of removing any glass blanking plates at a later stage? It's not the easiest thing in the world to do!

 

[mcox]

I was just planning on screwing in a cap until ready to use. Is that what you mean by blanking? Thanks for the advice on the holes. They will be evenly spaced across the top and the ones that would be half way down would be about 1 foot from the other holes and offset.

 

[windsor-aquatic]

I assumed that you were going to silicone a small glass plate over the spare holes. If you can blank them off with a cap, that's a better idea.