ok check this out guys. bought 110 gallon aquarium used about 15 years old. the guy filled it up no leaks. but when i took it home some of the sealant on the bottom was peeling some of the sealant was missing on the bottom.but half of the tank sealant was is in good condition. to make sure it dont leak on my floor. i took out half of the bottom and bottom corners resealed it letting it dry 36 hrs. but then i read a forum that said u should all the sealant out and replace it. i just dont see it nessary to take out perfectly good sealant. i cleaned the old sealant and wiped new sealant over it. what do u guys think?