2 years ago when I had a 75 (my biggest tank atteh time) spring a slow leak, I figured that since I already have to remove the fish, pump out all water and take out decor/gravel to reseal it, I would be half way through selling the whole thing (just short of finding a buyer who will come and pick it up). So I went ahead, resealed it but instead of filling up with water again, posted it on eBay. That baby flew out and I had something like $400 to put towards a new 125. If I am not mistaken, the argument I used on missus was "I just don't feel safe having this old tank anymore! What if it leaks again causing property damage?"