Fish have to go to the bathroom. When they go to the bathroom, they create ammonia. Ammonia is very toxic to fish. So what you have to do is cycle the tank to build up nitrAte. NitrAte converts the ammonia to a substance that is virtually harmless to fish. It takes about a month to do this, and there are a few ways.
One of the ways is to have mature media. This will jumpstart the cycle, and you will only have to add amonia for about a week.
The second type is a fish-in cycle. This is where you cycle the tank with fish in it. This method consists of very large water changes multiple times a day.
The last type is fishless cycling. This is where you add ammonia to the tank and wait for it to lower in a couple of days. And then you add more and so on. This method takes about 3-4 weeks to complete.
So basically, you will need to cycle your tank to keep your fish nice and healthy. I'm not the best at expaining thigs as you might be able to tell, but I hope that you understand!
Nitrate does not convert ammonia into a harmless substance.
Ammonia is converted, via beneficial bacteria, into Nitrite, then another type of bacteria convert nitrite into nitrAte.
Nitrate is the end product in the nitrogen cycle.
-FHM