That's too bad seller wasn't honest about that - assuming it did exist prior. I see where you said is wet, but where is it leaking?
I'm not sure where exactly it's leaking. I'm guessing somewhere at the bottom where the back meets the bottom. The silicone all looks pretty good, so I don't know. The seller swears he had no idea it had a leak. My husband pointed out some water marks in the wood on stand. But it's in the back, so who knows, maybe it's a leak from moving, maybe it was small enough he didn't notice the leak, maybe he knew. Doesn't really matter now.
My husband is trying to encourage me to just reseal it. I've been reading the forum about silicones used, and oppions vary so much, I'm clueless on what to use. It's so much water volume, I want to use whatever is best! I've watched some videos on how to reseal. Looks fairly simple, but they are doing 10-20 gallons.
Then there is in the back of my mind when I was a kid helping my dad reseal a tank, I had a horrible allergic reaction and had to go to hospital. The Drs never did an allergy test, but bc of what I was doing at the time, they told my parents I was allergic to silicone. Ugh! I haven't touched it in the wet form since. Lol, maybe if I do all the grunt work of cleaning and taping I can convince my husband to do the actual silicon application when I'm not home. The fish are my hobby, not his.