My family will be in Atlanta the first week of July & hope to visit the aquarium on the Wednesday of that week (July 2). I'm wondering if we need to buy our tickets on-line before we go. I recall people having to do that when it first opened b/c of its popularity. Is this still the case & is it likely to be especially busy during a holiday week? This is probably our best day to go & I don't want to blow it by not being able to get in. Any thoughts or tips? Thanks!