Life expectancy of silicone

[Europhyllia]

not too long ago somebody posted life expectancy of tanks but now I can't find it. I think it was in reference to how it's shortened by the use of waveboxes.
What was it? 10 years? 15 years?

I am leaning towards buying a new tank but wouldn't want to miss out on a good deal on a used tank.
At the same time I would hate to be the one that fully stocks a 215 gallon tank and then the silicone fails and leaks all over the place and me having to find somebody to reseal the whole thing...

[alton]

My brother inlaw has a 55 Oceanic that is 20+ years old. I would think the silicone caulks are better today than ever. Tank quality I would think is number one. It is hard to beat the old Oceanic and how they where buiilt especially if it came out of there custom shop. I had an expeirence one time setting up my bosses tank. His daughter did not want an aquarium stand in his office so she had a piece of furniture built and while filling it up the furniture cracked and busted. So we pumped all the water out and after all the water was out we noticed the stand on the left side had dropped 1/2" leaving the aquarium to support itself. The furniture company built a much stronger piece of furniture the second time and still today there are no problems. And it has been setup since 2001. The tank is a Oceanic Brick 60" x 18" x 29"