This week I aquired a 10 gallon tank from a customer. I'm a cable technician/guy and the previous homeowner had left a bunch of stuff behind. I asked the new homeowner if I could take the tank off his hands and he said sure.

Anyway, the tank has a sticker on it that says "inspected 1996", which is when it was made. I currently have the tank sitting outside, full of water to test for leaks. After one day it's still holding.

How long should I let the tank sit full of water before I can be sure that the seals are good?

It should be safe to use since it hasn't leaked. However, if you are really worried about it, then just reseal it. its only a 10g tank. it be a piece of cake.

I have a 55 gallon that I bought 17 years ago.. Don't know when it was built(bought it new) and it still holds water.. The silicon holding it together is still in great shape.

Ok, that makes me feel better. The silicone seal on the tank looks really good.

A 10 is much lighter even when filled with water, so the silicone is much less stressed. Ought to hold up a long time.

I have tanks that are about that old, 10-20 gallons, and they are fine.

The ones I am having problems with are a few I acquired from someone who kept them outside, subject to the hot and cold of being in a barn, dry. I have been able to reseal only one of them (the shallowest), I think I have to totally rebuild the other 2. The seams have popped open more than once, when all I did was reseal.

If its holding water, your more than likely good to go. However, if it did have a leaky seal, in my opinion, a 10g is not worth it. Just get a new one. I have resealed a 55g and a partial seal repair to my 90g tank. To get a good quality seal job, it takes a bit of work and patience. Its much easier and less of a hassle to just buy a new 10g if need be. Especially during the $1 sale when petco runs it. On a bigger tank, I am definitely on board with resealing. Anything less than 20g, I wouldn't bother. I would break the tank down and use it for scrap glass.

Ok thanks. The tank held water outside for 3 days, so yesterday I brought it inside and cleaned it. On a side note, I quit my job that allowed me to get the tank.

Hopefully to take a better job.