Ah, you'll be fine. I work at the Parafield store. This is what you'll be asked... What model tank is it? Where is it leaking from? Make sure the filter isn't overflowing or splashing, which may cause dripping over the side. They'll then ask you to bring in the tank (depending on the size btw) and they'll fill it up and check for leakage.. Perhaps, if you are able.. take a video of the leaking while it's still at home? Might be a little easier to deal with
You should have been signed up as a pet stock member when you bought the tank. The purchase will be recorded on there, which makes life easier
Sez