Hi dirtbiker and Welcome to TFF!
As we've said in several threads lately, the LFS is just like the lumberyard, you just go there to pick up wood - they won't teach you to be a carpenter! They'll never tell you that the filter you bought is just a kit. Its meant to be given a couple of months (!) of rather tedious work prior to it being ready to handle any fish at all.
When fish move water past their gills, they give off ammonia (NH3) as well as CO2. Fish waste, excess fishfood and plant debris also combine to break down into ammonia. Ammonia, in even tiny amounts, causes permanent damage to fish gills, causing a shortened life or death. In nature, the ammonia is carried immmediately away from the gills by millions of gallons of fresh water. In the aquarium we have an amazing machine, the biofilter, to clean the ammonia out of the water, but the way it works is that a large colony of live bacteria (the bacterial species is Nitrosomonas) attach themselves to porous media in the filter and they -eat- the ammonia! It can take up to two months or so to grow a sufficient colony of these little beasts. If your fish don't have their little bacteria friends in that working biofilter, they are like people locked in a garage with some running dirtbikes, they're desparately searching for airholes so as not to breath the carbon monoxide (ammonia, in the little fishies case!)
About now you're thinking: "Oh, that's why they sold me the bottle of bacteria!" but unfortunately that's a sham. The bacteria won't have lived past a day in the closed bottle and its sold because beginners only vaguely know there's "something important about bacteria and fish tanks" or such. The painful truth is that the beneficial bacteria are very, very slow growing and must be the correct ones and well established before the magic of the biofilter will work.
I'd like to note also that the biofilter is even more interesting than just the ammonia part. The ammonia eating bacteria (or ammonia oxidizing bacteria.. we call them "A-Bacs" for short) process the ammonia (NH3) and produce nitrite(NO2) which, unfortunately, is -also- a deadly poison for the fish! Amazingly, there's yet another species of bacteria (Nitrospira) that like to grow in the same places as the "A-Bacs" and they like to eat nitrite(NO2)! What these Nitrospira (also called Nitrite oxidizing bacteria or "N-Bacs" for short) do is eat the nitrite(NO2) and produce nitrate(NO3) which is not great for fish but is much, much less toxic and can be removed with a weekly water change!
OK! So there's this miraculous device, called the "biofilter" out there that's been used by aquarists for over a hundred years but yours isn't working yet! What to do?
Its ok, we get lots of people in this state of affairs every week. You are in what's called a "Fish-In Cycling Situation" and there's no guarantee that we can save the lives of your fish or that they will live long after this but we can try to give you the best info possible to hopefully turn the situation around: What you need to do is perform some large (50-70%) water changes where you remove that water using a gravel-cleaner-siphon (gravel cleaning as you go) and then replace the water with tap water that's been conditioned (to remove chlorine/chloramine) and roughly temperature matched (your hand is good enough for this.) You can repeat this procedure as soon as one hour after the previous time and it may take two or three water changes before your fish will begin to behave more normally.
Meanwhile you need to be getting your hands on a good water testing kit if you don't already have one. The paper strips are useless. Many of us like and use the API Freshwater Master Test Kit or the Nutrafin Mini-Master Test Kit. Once you get this kit report back here and the members can help you use this kit to be a detective and see whether you really need so many water changes or not. There's an article on the Fish-In Cycling technique in the Beginner's Resource Center.
~~waterdrop~~
mate 
