I thought it would be a good idea to briefly talk about "Cycling a Fish Tank". Now, if you search the Internet, you will find so many different ways of cycling a tank, it could become very confusing. Many people do it in different ways but at the end of the day, they normally end up with a properly cycled tank. If like most people you only plan on having one tank, this is a procedure that you should really only have to do once, unless you have a disaster at some stage.  This is just the way I do it.

What does cycling a fish tank mean?

Keeping fish in a fish tank is a huge compromise compared to what their life would be in the wild.  Most fish that we keep live in literally millions and millions of gallons of water, they don't have to worry about ammonia or nitrite. However, once you put a fish in a small amount of water, the whole situation changes dramatically.  If you don't do things properly, you'll poison the fish to death.  What you are trying to do is create a mini environment for the fish to live in.  Obviously it is never going to be as good as in the wild, but you have to strive to make it as safe and liveable as possible.   Before you add any fish to a tank, it is vitally important that you prepare it properly so that the fish have a suitable environment to live in. It is not just a case of filling a tank full of water and plonking your fish in it.  People who are new to fish keeping often go out and buy an aquarium set up, fill it with water and then just add their fish. They then start wondering why the fish start dying within the week. Basically, the fish are being poisoned to death by their own waste. A basic complete aquarium setup consists of the aquarium itself, a lighting system, a heater, and a filter.  The heater and lighting are self-explanatory.  However, the filter is a little bit more complex than a lot of people actually realise.  Newcomers to Aquatics tend to think that the filter is just for removing debris from the tank.  Yes, the filter does this, but that is only half of the story.  Your filter is actually the heart of your tank, without it, your fish will not survive.  Whereas a brand new filter will remove solid waste, it will not remove dangerous toxins.  The filtration system will only do this once you have the correct bacteria living within it.  Growing bacteria in a new filtration system is commonly known as "cycling". 

When the fish goes to the toilet, ammonia is produced  (NH3, NH4). In a tank that has been cycle properly, the nitrifying bacteria that inhabit  the filtration system turns ammonia into nitrite (NO2) which is then turned into nitrate (NO3).

So basically, cycling a fish tanks means establishing a biological filter.

Cycling a Fish Tank

There are two ways that you can cycle a fish tank. You can either do it using fish, or do a fishless cycle. Seedling your tank at the very beginning is always a good idea. What this means is you add bacteria to the aquarium. There are various ways you can do this.

 

Use gravel/water or both from an existing cycled tank

 

Using filter media from a cycled tank (squeeze sponges out into your new filters or if you are using external filters with ceramic media, pour water out of the trays into the new filter. If there are any little bits of debris, put that in as well. 

 

If you are not intending to use the old existing media then you could incorporate it in with the new media. Some people cut sponges up and add it into the new media. If you are using ceramic media, you could mix it in with the new media

During the cycling process you will need to test the water.  You can either do this yourself, or get your fish shop to do it, they normally do it for free, or for a very small for charge. It is actually very easy to do it yourself, it is just a case of putting a few drops of a special chemical into a vile containing some tank water and then waiting for a few minutes to see what happens.

Once your tank is full of water, treat it to get rid of the chlorine. Chlorine and the beneficial bacteria in a fish tank don't mix. Chlorine will kill bacteria very quickly so beware. Go and get yourself a few hardy fish. Tetras, barbs and even guppies are good for cycling the tank. They are all cheap so it's not exactly a case of losing expensive fish if one of them does die, which will be a distinct possibility since they will be exposed to non-than perfect water conditions.

Don't be tempted to add too many fish straightaway, take it easy, you don't want to overload the system straightaway.  If you do add too many fish, you could well overload the biological filter which could cause the tank to go into a mini cycle. This means that the ammonia and nitrite could suddenly be present once again. You would then have to go back to doing water changes every other day until the bacteria has got a chance to catch up.

Bacteria In a bottle

As mentioned at the beginning of this page, you can always do a fishless cycle. A fishless cycle is exactly how it sounds. You cycle the tank without fish. What you do is use pure ammonia. This is often found in hardware stores. Having said that, it isn't always easy to come by so you may have to look around. A fishless cycle is a lot easier and more convenient than cycling the tank with fish. For a start, you don't have to do any water changes and more importantly, there aren't any fish that are put at risk from high stress levels that would be caused by poor water conditions. For a more comprehensive look at a fishless cycle, visit this website

http://www.tropicalfishcentre.co.uk/Fishlesscycle.htm