Sealing a hole

[Intheflesh]

I recently picked up a tank that is drilled for a center over flow on the bottom panel. (18" cube)

I really don't want to use a center overflow, and was thinking of the best way to patch the hole.

Option 1: silicon a plate of glass the same thickness as the bottom panel +1-2" over lap.
Option 2: just put a threaded bulkhead with a PVC plug.

I'm worried about option 1 cracking over time, and #2 leaking over time. What would you suggest?

I am looking to move the overflow to the corner of the tank using an Xaqua In-out

 

[QUIG]

I have a 175 that was drilled and the prior owner put a type of rubber membrane over the holes with silicone. I've had it filled in my basement now for over 2 years and no leaks, but use it as a fresh water tank.

 

[delta]

You could do either way glass or Bulkhead. But if done right the glass will be a more permanent solution. I would find someone who is well versed in glass tanks/Sumps. And let it cure fully at least 2 weeks for me I would wait 28days. Problem with the Bulkhead is if you do not put a overflow around it. the is greater chance it will fail than a glass patch and you would have to drain the tank if that happened.

The glass you would use a large piece. if you look at glass cages tank that are reinforces in along the edges with a strip of glass on the bottom pane of the tank

 

[Intheflesh]

I think I may need to take a long hard look at the tank and decide if I really hate the center overflow that much....

Kinda wish I waited for an un-drilled tank, but I couldn't say no for the price!

 

[daves-reef]

I had similar in my 20 gallon refugium someone gave me. I needed to drill side not bottom for my space. I went with option 1 glass and silicon, been running over 5 years no leaks.