Tank Drilled...now it's leaking...Help!

[sumpfinfishe]

Hi Michael,
Well sounds like a setback, better now when it's empty though rather than when it's full of life 6 months down the road
I would re-seal the entire tank if it was me, just incase the previous owner stressed the seams during there ownership.
I have a glass Hagen tank, and the folks there told me that the silicone is only good for about 8-10 years-salt and cleaning magnets are a major cause, not to mention transporting.
If you have never used silicone before, I would suggest asking a friend who is in construction or is a handyman to do the job as silicone can be tricky. If you want to do it yourself and have not used silicone before, then I would suggest some practice on a scrap few pieces of glass.
You will also need to remove all the old silicone before applying the new, and also be sure that the glass is really clean and dry as silicone leaves a residue that can be hard to see or feel.
What your looking for is a nice thick even beed that is applied in one long stream with no gaps or thin areas, as well as no air pockets. After a thick beed has been aplied, you will also want to lick your finger(prevents sticking) or use a corner of a small piece of cardboard and run it along the silicone to make sure that you get an even coat on both sides of the glass and also to fill any air pockets left behind the beed. This is the tricky part as you still want a nice thick even beed between both panels of glass, but also you want to just smooth out the beeds and not simply smear silicone all over the place.
You need to use an aquarium safe silicone for sure I buy mine at my LFS, but they also sell it at some home improvements stores too-just make sure that it's aquarium safe-it will say right on the box or tube that it's none toxic and aquarium safe.
If you don't know anyone with silicone experince and your not 100% comfortable doing it yourself then I wouls suggest doing all the grunt work of cleaning the glass and then I'm sure you could find a local glass shop to do the silicone for you at a reasonable rate
Goodluck
Cheers, Rich