bottom Corner Chip

It looks like the tank was dropped on that corner. I wouldn't want to risk that holding water inside the house. Sadly the best solution is probably to buy a new tank. For what it would cost to fix and the amount of work involved a new tank might actually be cheaper.

Well if you want to risk it is up to you. At the very least I'd want to do a reseal and add some glass strips to reinforce that corner. That means removing all the old silicone inside the tank, wiping it down with acetone or denatured alcohol to remove any silicone residue and then applying the new silicone. The new silicone had to be done all at once and fairly quickly so that it doesn't start to cure before you finish. This is because new silicone will not sick to old silicone. You'll need to add the glass strips to reinforce the corner at that time too. I used about 2 1/2 of the tubes that fit into a caulking gun to do a tank about the same size as yours.

The are threads on how to reseal a tank on here with more complete information.