Please read about cycling aquariums in the second section of Immediate Help. Google Nitrogen Cycle for a second set of opinions. We don't want too many fish to start that process or we will kill some off.

Your situation is sounds a bit similar to the log submitted just after yours - Unusual Behaviour or not???

I fear the issues there are related. Have you done a partial water change this week? Was the water treated before hand. Is it the same temperature as that of the tank. Do you have water containers and space to let the water sit at least a day (a week is better but maybe unrealistic)? See my comments on what can be done in a hurry in the unusual behavior comments.

Sometimes it is because new aquarists are suffering from information overload, sometimes because the fish seller neglected to mention several important elements of establishing an aquarium. But (and if you are already familiar with these things, I apologize for wasting your time) you need to know what the nitrogen cycle is all about. Even though it will slow down the cycling of the tank, you need to know that partial (at least weekly) water changes will keep the ammonia and nitrite spikes and eventual nitrate accumulation from becoming too stressful (ie toxic) for your fish.

And if they didn't tell you, it really is wise to have test kits for ammonia, nitrites and nitrates. New aquarists can go find and play with other test kits later in the hobby, but testing for those items should be an important part of what a newbie does. If buying test kits is a hardship now, see if the shop will test water for their customers. (Of course in time the gasoline spend driving to the shop may cost more than the test kits, but it may be a good stop-gap strategy.)

Another costly item which is often ignored, in addition to testing, is a quarantine tank. Since an awful lot of the fish from a shop will be diseased, a $40 quarantine tank (10-gallon tank with an airstone run by the air pump running your other filter - tap its airline with an adjustable valve or t-valve. thin layer of gravel, plastic plant or two, submersible heater and glass top) will cost you less than what you will otherwise lose from the first two or three times you just introduce new fish into your aquarium.

As Australian physician and fish head Bruce Hansen has suggested, the quarantine tank is for the benefit of the fish in the regular aquarium. It is so if the new fish are diseased and die, they will not take everybody out in the established aquarium. If the new fish get sick and can be successfully treated, wonderful. But the odds of effectively treating columnaris (for instance) are very slim. Better to lose the new purchase than old friends.

Those observations about quarantine tanks sound a little harsh. But that is better than losing all of your fish, getting really frustrated and dumping the tank out on garbage pick up day in a few weeks.

Now, I'll shut up and maybe we can both get off-line and try do do some water changes and/or tests. :)