hello; Silicone has a shelf life. Might be better to locate a source. Look for a date if you do not plan to use it soon.About 60 gallons, I ended up getting rid of it this weekend because I'm going to be moving soon and it would be easier not to have it for the move and I could Craigslist another tank once I'm settled in. That aside thanks for all the help and product recommendations, I'm thinking I might pick up some of that silicone Big-G mentioned just to have it on hand if this happens again after my move.