I've resealed some aquariums before, and one of them several times lol. One day I came across a 300 gallon aquarium on craigslist for $100.00, yes believe it lol. I went to go check it out, the guy that was selling it told me that it was leaking from one of the sides, the silicone seamed old and it needed to be replaced. We did a water test and sure enough it leaked. I decided not to buy it, the guy even offered me to take it for $50, I still said no since I had no clue on how to reseal and was new to the hobby. I regret that decision for the past few years. Some time after I picked up a 55 gallon that was leaking all over. It was free by the way. I was curious on how to reseal the aquarium, I watched several videos on YouTube and read some good info on this site. I gained confidence and decided to strip it out and reseal it. To my surprise it worked and was not as hard as I imagined. I was not leaking, but the seams were not perfect, so I decided to remove all silicone and re do it. I did it 3 times, not because it would leak, but because I decided to perfect my resealing skills in case I ever found another great deal on craigslist. Ive resealed some aquariums for friends, nothing large that 55 gallons, but now I am confident I can reseal any size aquarium. I would suggest to think positive and reseal it as soon as you feel confident, if you are not pleased or it leaks, try it again its not hard, perhaps time consuming but at least no irreversible damage is occurring to the aquarium. Hope it this helps, good luck.