I would think you'd be okay for a couple of hours. After that, you'll need to get creative. Definitely get some water movement in there, even if its scooping a cupful and dumping it back in just to generate some air.
In the future you might want to invest a battery powered air pump:
http://www.jlaquatics.com/product/ap...+Air+Pump.html
They work like a hot damn and are a lifesaver
