I've added Stress-Zyme and the recommended dosage of aquarium salt... the bacteria in the Stress-Zyme should be what I need, right? I know my biological filter needs a good kick in the pants to get started back up again, but I can't imagine what could cause ammonia to just appear so fast in new water.

Will Bio-Spira do something that Stress-Zyme won't? I'll go out and get some tomorrow if it will.

Also - zeolite? I've never heard of that, but I just looked it up. Is that necessary to get, and if it is, how would I go about adding it to my filter? I'm using a Penguin Bio-Wheel filter, so I'm not sure that it's something I could just add in.