Guides - Tank Cycling.

Once you have figured out what kind of fish you want to keep, and you have gotten your tank and all its equipment, and you have your tank set up you're ready to get fish.

Well, almost.

Before you get too many fish in the fish tank, you need to get your biological filter established. This is a process that takes six to eight weeks and is commonly referred to as "cycling the aquarium," "aquarium cycling," or just "cycling".

Your aquarium filter should do two things for your aquarium. The first is to filter out debris floating in the water. The second, but more important is to process the fish's waste in to less toxic substances.

The first, your filter can do straight out of the box. The second requires some time to establish. Getting this second part of the filtration process going is what cycling your aquarium is all about.

Your fish produce waste in various forms (they go to the bathroom) in the water constantly. Most of this waste becomes ammonia fairly quickly after exposure to water. Ammonia in the water is toxic to the fish.

In your filter, a colony of beneficial bacteria will grow. They will process the waste from ammonia, to nitrite, to relatively harmless nitrate. However, it takes 6-8 weeks for this colony of bacteria to grow and mature in your tank.

So, how do you get the bacteria?

These nitrifying bacteria are ubiquitous. They're everywhere. Unless your home is hermetically sealed and no one every enters or leaves, there will be some living in your home. When the fish tank becomes available and has a source of ammonia (bacteria food) the bacteria will move into the fish tank and start a colony.

All right, so we know what the problem is, and that there are free bacteria that will take care of the problem. What now?

Well, you need to get fish waste (ammonia) into the water. The easiest, simplest, safest, cheapest way to do this is with a small number of fish. You'll want one or two small, hearty fish for every ten gallons of aquarium water. You want small fish because they'll produce less waste and therefore be less likely to harm themselves with their own waste during this process. You want a small number of fish for the same reason. You want hearty fish because they will be less bothered by the elevated waste levels if you don't keep up with the water changes (I'll get to that in a moment) and the waste does start to build up.

You also want to select fish that you want to keep in your tank in the long run. Remember, these are living creatures that you have taken on the responsibility of caring for.

Once you have your first few (very few) fish, your tank can begin to cycle. The tank can't begin to cycle before you have a source of fish waste in the tank.

However, at first the filter can't deal with any of this waste. How do you deal with that? Well, as I mentioned above, you start with a small number of small fish. Then you keep your feeding minimal. Excess feeding will produce additional waste that the filter can't deal with yet. Finally, you do a bunch of water changes.

While the tank is cycling, a process that takes six to eight weeks, you need do do extra water changes. You should do a 10-15% water change at least twice a week. You also want to do an additional water change any time you see signs of ammonia stress in the fish in the tank. this will keep the ammonia and nitrite levels low in the fish tank while it is cycling, and eliminate (or at least minimize) any stress that your fish would experience from the cycling process.

As previously stated the cycling process takes six to eight weeks.Once you have hit the eight week mark, you can cut your water changes back to the one 10-15% water change per week that the tank requires for standard maintenance. Watch the tank for the next two or three weeks to see if you see any signs of ammonia stress, and if you do, do an extra 10-15% water change. When the tank can go a week between water changes without signs of ammonia stress, it is cycled. Give the tank at least two weeks after it has finished cycling before introducing any additional fish, just to make sure everything is stable.

NEA - Test kits are available in many forms and these will help you with a more accurate reading as to what the levels of ammonia, nitrite and nitrate are as well as ph and hardness etc. If you have any questions feel free to join our forum here at Northeast Aquatics and ask for advice.