On Wed, 13 Jan 2010 20:37:17 -0500, news.eternal-september.org wrote:

I can't figure out how one would go about fixing this kind of leak.

If it's that small a leak, and the surrounding material is in good shape,
they make screw-in patches for those.

That's yet another potentially viable solution.

So far the solution might be:
0. Empty tank and look for the hole on the bottom
1. If small (pin hole size), use a screw-in patch from the inside;
2. If larger, weld a patch plate from the inside;
3. If too large, consider if they make tank-repair bladders;
4. If not, lift the tank, cut off the bottom, & weld on a new bottom;
5. Or, replace the steel tank with a new "poly" tank.