The "additives" bottle is almost certainly NOT bottled ammonia - it is a "bacteria in a bottle" product. Many people, myself included, believe these products are next to useless. I can see how they might be beneficial when used alongside bottled ammonia, but even if there are live bacteria in the bottle, they can't be that great until they have some food and that food is ammonia.
I can pretty much guarantee that right now, at this very moment, your tank will be perfect for fish - because there is nothing in it that will make it not-perfect. The moment you put a fish in there, it will start to produce ammonia, but you won't have sufficient bacteria in the filter to process this ammonia and consequent nitrite, and you will poison your fish. Have a read-through of some of the threads in the Emergencies section - "Why did my platy die" is one, there's also one I've just replied to about a danio that's been suffering, and swimming at an angle.
At the top of this section of the forum is something called the "Beginners Resource Area". In there are two articles that you really, really need to read. One is called The Nitrogen Cycle - it gives you all the theoretical stuff. THe second is called "Fishless Cycling" - this tells you how to grow the filter bacteria without harming any fish (and it's a lot less work than trying to do it with fish in the tank. I should point out that it's rather out of date, particularly the "Add Daily" method, and in the very near future, it will be replaced with the latest thinking, but in the meantime, it's a good read, and it tells you stuff that most LFS won't tell you - because it's not profitable for the retailers to do so.
You also really need your own tests, rather than relying on the LFS. I personally recommend the Salifert and Nutrafin ranges, many others recommend the API kit.
