I guess everyone has there own way of doing it but I think many people use far too much glue. I glue the joints glass to glass with no extra glue between. The glass is all pushed firmly together and held there till dry. 99 % of the time a tank like this will not leak. A small fillet of glue is added to the inside of the joint to make it easier to clean (rounded corners), to improve the looks and add a little more strength. If you look at the imported tanks made in china they use very little glue, look great and don't leak. We used to make 10-12 600x300x300mm tanks (12 gallon) with a cartridge of glue. The more glue you waste, the longer you need to wait.Very large tanks are of course a bit different.