The Nitrogen Cycle is something that occurs naturally in the oceans and other waterways where fish live. Because they now live in a home controlled by you, it is up to you to make sure this cycle occurs in your aquarium just as it does in nature. You will need a Test Kit for this. It is very important that you provide oxygen for your aquarium water. In order for the Nitrogen Cycle to perform properly, the bacteria need oxygen! You can provide this by putting an air stone (a stone hooked up to your air pump that will give off bubbles of air), a bubble wall (a piece of tubing with holes in it that you hook up to your air pump and will give you a neat wall of bubbles) or what we call "aerating" ornaments (ornaments that blow bubbles of air out of them. These are really cool! They also need to be hooked up to your air pump.) Which ever one you choose is fine, as long as you provide extra oxygen for your fish.
You will also need to learn some new words. The first one is:
AMMONIA - This happens in your aquarium when waste from your fish (when he goes to the bathroom in the water) and food that your fish has not eaten lays in the bottom and rots and decays. Both of these things cause ammonia to form in your aquarium. This is very harmful to your fish and if not controlled, will kill your fish. So, nature takes over to form a bacteria called:
NITRITE - This is a good bacteria that comes to life because there is ammonia in the tank for it to feed off of. Nitrites are also very bad for your fish but not as bad as ammonia. So, nature comes to the rescue again and forms another bacteria called:
NITRATE - This bacteria feeds on the nitrites and takes them out of your water. Other little organisms in your water will feed on these nitrates and if you have too many of them, you will have an excessive algae (that green stuff that will grow on the sides of your tank) growth. To control too many nitrates, you should do a Partial Water Change. This is why it is important to test your water often to make sure your water is safe. Following is a time table for you so you can see how long the completed Nitrogen Cycle should take to complete. So, when you put your first fish in your aquarium, follow this schedule as closely as possible:
7 - 10 Days - Ammonia level should be at its highest and quickly drop as Nitrites begin to show up. Do not do any water changes yet. Only add some water from your containers (after testing them for chlorine) to make up for any that has evaporated. Also do not clean any of your equipment or anything else in your tank. I'll explain later.
17 - 19 Days - Nitrites start doing their job and your ammonia level will drop quickly.
21 - 28 Days - Ammonia and Nitrites should both be at "0" and the nitrates are now present in your water. NOW YOU CAN ADD MORE FISH! You should also do a 10% to 15% Partial Water Change. 10% is not very much, so scoop some of the water out and replace it with the water you have sitting in containers. NEVER PUT WATER IN YOUR AQUARIUM RIGHT FORM THE FAUCET! Only use water that has been allowed to sit for at least 3 days. Test it for Chlorine before you pour it in your aquarium.
What you can't see happening inside your tank is that all of the surfaces (all of your decorations and plants and filter and everything else in there) are covered with good bacteria that will continue your Nitrogen Cycle. It is very important that you do not disturb this balance by washing any of those things with water. Only wash off your filter or any ornaments, if they need it, in water you have taken out of your tank when you do partial water changes.
