sealant

I bought two 75G Aqueon tanks from Petco on $1 per gallon sale. These tanks are cheaply made with the littlest seal possible. The seams look okay but the silicone on the inside corners are very little and thin. I know resealing a brand new tank sounds like an obsessive compulsive disorder but I...

I am looking for a tube of black aquarium sealant locally. I have to reseal a 75 gallon.