Leave it in there for a couple of weeks, or a month if you're uncertain. Oxygen is usually fine in your tank unless it's overstocked, albeit I'm sure your levels should be fine if there was water movement on the surface. Ph problems might fluctuate depending on your tap water, it could be high from the tap, but drop down after some time.
Did the LFS show you or tell you what your Ammonia and Nitrite levels were?
Edit: DavidR, link was good laughs.