Where's the best / safest place to drill a hole?

[Oreo]

I have a 110gal tall (48x18x30) glass tank from Perfecto. I need to put 3 bulk heads in. Two will be 1" for the filter inlet / outlet & one will be 1/2" for overflow for the tap water drip system.

I was planning on drilling these holes in the large back glass panel. The two for the filters will go up near the tank rim, & the one for the overflow will go about half way between top & bottom.

Then I started thinking about the integrity of the glass. Is what I'm planning safe? Any chance I'm unduly weakening the glass with this layout? If so, what would be a better layout?

 

[bigbaddad]

My advice ditch the drip system use a sump,drill one hole for your water return and one for your drain. If you drill your holes about an inch away from the top you will keep alot of the tank's integrity.

an overflow is useless when drilling a tank simply use a larger scale sump fill the tank until it starts to drain into the sump when the sump is full that is your overflow just make sure that when you turn the pump off you did not ovefill the tank and sump.

This is what i chose to do.

 

[daleros]

You will be fine. Just stay a minimum of 4 times the thickness from the edges. I personally would stay 8 times for a thin walled tank. ie the glass is 1/4", stay 1.5" (.25" X 8) from each edge and the adjacent hole. A hole in a pressure plate doesn't weaken it that much. Plus, a good bulkhead reinforces the hole. I have heard of people using threaded PVC pieces and bushings. Although this works for leaking, it doesn't have the reinforcement flange. Also, follow the DIY tips for drilling and the manufacturer's recommendations.

 

[Oreo]

I'm using a canister filter setup, so the sump / overflow isn't an option.

Glass is at least 3/8" & maybe 1/2" thick. Thanks for the tip about keeping the holes away from the edges. I will be using real PVC bulkhead fittings.