Kaix
05-03-2006, 09:59 AM
The Basics of Cycling
The term 'cycling' is applied to the process, which takes place as a new aquarium 'matures'. This refers to the build up of essential bacteria, which break down wastes. The implications of this are probably the single most important factor in maintaining healthy fish.
In a new aquarium, there is not enough bacteria to cope with the waste load and ammonia can rise to dangerous levels. Eventually, the bacteria increase to cope with the ammonia, converting it to another, less toxic compound - Nitrite. This too will then rise to high levels until a second type of bacteria increases and converts it to the much less toxic Nitrate. This process can take several weeks. In the confines of an aquarium, there is not really a complete 'cycle', and most of the end product, Nitrate, is normally removed by water changes as shown in the diagram above.
There are therefore certain things, which should be done to minimise any stress or even fatalities during the cycling period:
Add only a few hardy fish at first and feed lightly to minimise wastes.
Test water regularly and perform water changes to reduce the levels of ammonia and nitrite if they become dangerously high. The bacteria are attached to surfaces, so removing water should not slow down the maturing process.
If possible, obtain some gravel, tank decor, plants or filter media from a mature tank. This will introduce some of the necessary bacteria and may reduce or even eliminate cycling time.
The aquarium is considered 'mature' when ammonia and nitrite have reduced to zero, and nitrates have begun to rise. At this point it will be necessary to begin a regular program of water changes to keep the level of nitrates low.
You should aim to keep the nitrate levels as low as possible.
Fish waste
Uneaten food
Plant matter
Wastes
AMMONIA
NH3
Conversion
by bacteria
NITRITE
NO2
Conversion
by bacteria
NITRATE
NO3
Removed (mainly)
by water changes
The term 'cycling' is applied to the process, which takes place as a new aquarium 'matures'. This refers to the build up of essential bacteria, which break down wastes. The implications of this are probably the single most important factor in maintaining healthy fish.
In a new aquarium, there is not enough bacteria to cope with the waste load and ammonia can rise to dangerous levels. Eventually, the bacteria increase to cope with the ammonia, converting it to another, less toxic compound - Nitrite. This too will then rise to high levels until a second type of bacteria increases and converts it to the much less toxic Nitrate. This process can take several weeks. In the confines of an aquarium, there is not really a complete 'cycle', and most of the end product, Nitrate, is normally removed by water changes as shown in the diagram above.
There are therefore certain things, which should be done to minimise any stress or even fatalities during the cycling period:
Add only a few hardy fish at first and feed lightly to minimise wastes.
Test water regularly and perform water changes to reduce the levels of ammonia and nitrite if they become dangerously high. The bacteria are attached to surfaces, so removing water should not slow down the maturing process.
If possible, obtain some gravel, tank decor, plants or filter media from a mature tank. This will introduce some of the necessary bacteria and may reduce or even eliminate cycling time.
The aquarium is considered 'mature' when ammonia and nitrite have reduced to zero, and nitrates have begun to rise. At this point it will be necessary to begin a regular program of water changes to keep the level of nitrates low.
You should aim to keep the nitrate levels as low as possible.
Fish waste
Uneaten food
Plant matter
Wastes
AMMONIA
NH3
Conversion
by bacteria
NITRITE
NO2
Conversion
by bacteria
NITRATE
NO3
Removed (mainly)
by water changes