PaiLum92;5128729; said:If you do decide to reseal, a normal tube of fast drying caulk would work fine. You just have to make sure it sits for a couple of days in the sun to make sure its non-toxic when you add fish. (Basically make sure its Cured). Also wouldnt hurt to run water in it for a week afterwards, just to make sure.
CAULKING?! Do you want to kill your fish? ALOT of caulking has an additive for mold, and it WILL kill your fish.
He should use GE1 Silicon is he is going to reseal his tank without getting "real" aquarium sealant.
He can also use PL Roofing and Flashing adhesive.. it's black. Used it in my koi tank.