drilled tanks

I think fishybiz idea is well thought (about using bulkheads and PVC plugs), at some point, you may want to use a sump or run tanks in series, and unscrewing a plug is easy compared to undoing a permanent glass patch.

+1

I think fishybiz idea is well thought (about using bulkheads and PVC plugs), at some point, you may want to use a sump or run tanks in series, and unscrewing a plug is easy compared to undoing a permanent glass patch.

I would use glass if it were me.  I think the silicone adheres to glass better than plexi or acrylic.  You could always just use a bulkhead with a pvc plug. 

You're right.
Better safe than sorry.
Thanks for the input.

inside, if you put it outside and the silicone gives for any reason you now would have a 1" drain hole emptying the tank quick where if it's inside water pressure keeps it tight and if it would happen to fail eventually it would be a slow leak giving you a chance to scramble to save the tankmates

Yes, they are glass.
I was thinking of using plexi just because I have some handy and it's easier to cut than glass. Does the patch have to be on the inside? I was thinking cleaning would be easier if I could get away with a patch on the outside, but I don't know if there would be too much preasure for the silicone to hold.

Are they glass tanks?  If so just silicone a small square of glass over the hole from the inside of the tank.

Anybody got a few tips on plugging the holes on drilled tanks. I recently bought a few drilled tanks for dirt cheap but I don't want to leave the holes with the plumbing in them. I was thinking a piece of plexiglass siliconed on one or both sides of the hole should work. Your thoughts?