★ The Aquarium Cycle - Illustrated Video ★

★ The Aquarium Cycle - Illustrated Video ★

Aquarium nitrogen cycle

The nitrogen cycle is a chemical and biological process that takes place in your fancy goldfish pond or aquarium.This process is necessary to keep your fish alive and without a properly cycled aquarium your fish will die. You cannot just add a fish to any size aquarium and think that it will live.


There are several steps in the nitrogen cycle. The first step starts with your fish. Your fish will slowly produce a toxic chemical know as ammonia, 24/7, through it's gills and waste. Next a type of beneficial bacteria will consume the ammonia, and produce a slightly less toxic chemical called nitrite. Another type of beneficial bacteria will then consume the nitrite, and produce the least toxic chemical called nitrate. The nitrate can still be toxic in high levels or concentrations. So, you will then need to remove the chemical nitrate manually by doing a water change at least once a week. For fancy goldfish you will need to drain or remove 50-90% of the water in the aquarium, and replace 50-90% of the water by refilling the tank with clean water and adding a water conditioner. 

These beneficial bacteria need to be present in the water in order for the nitrogen cycle to take place, and for your fish to live. Unfortunately, these bacteria will not be in the

water before you add the fish because they need the fish to survive and thrive. You have an entire ecosystem in your tank. If you add goldfish to a tank without beneficial bacteria your fish might suffer from toxic shock or poisoning and die. This means that you will have to carefully cycle the tank.

How to cycle a fancy goldfish aquarium

Fortunately, you can help to grow these beneficial bacteria in the tank. First you will need to purchase and place biological media in your filter. Biological media provides a safe place for beneficial bacteria to colonize and grow on. Then you will actually need to cycle the tank. 1-2 weeks before you add 1 fish to your aquarium, setup your tank with water and running filters, then add a small amount of goldfish food. Never unplug your filters unless your cleaning them. The food will begin to decay and microscopic organisms will turn the food into ammonia. The ammonia will act as food for the beneficial bacteria and your tank will begin to cycle. 1-2 weeks later, you can add 1, just 1, fish regardless of the size of your tank. Your tank will not be fully cycled yet so you will need to finish the cycling process before adding more fish. Everyday for 1-2 weeks you will need to drain and replace 50% of the water in the tank. The following week you will need to drain and replace 50% of the water every 2 days. If you have done this correctly then, you should have successfully cycled your fancy goldfish tank. It is now safe to add more fish, but remember the stocking guidelines. Allow at least 20 gallons or 80 liters for the first fancy goldfish, then 10-20 gallons or 40-80 liters for every extra fish added.

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Can I do a fishless cycle?

Cycled is often a misunderstood, or misused term. When we say that a tank is cycled we are NOT just saying that there is a colony of beneficial bacteria in your tank. What we are actually referring to is that there are enough microorganisms to safely process ALL of the ammonia or other substances. All fish produce ammonia but, they also produce a number of other chemicals that have cycles of their own, including aminobutyric acid and somatostain! However, most fish do not produce enough of these chemicals to cause any problems that cannot be solved by even MONTHLY water changes!

Goldfish are different because they produce absolutely massive amounts of many chemicals, including ammonia, somatostain, and aminobutyric acid! Some people believe in doing fishless cycles. Using the fishless cycle methods, aquarist add pure ammonia for the beneficial bacteria to feed off of and grow. This might be fine for most fish, but not goldfish. This is because goldfish produce a very large amount of ammonia 24 hours a day. In order to acquire the right amount of beneficial bacteria, you would also have to slowly add large amounts of ammonia 24 hours a day. Of course, when the little amount of beneficial bacteria does begin consume most of the ammonia, it fools the aquarist into believing that their is enough bacteria to handle the constant, LARGE, production of ammonia produced by goldfish. Furthermore, no amount of ammonia will help develop the microorganisms that deal with the other chemical being produced by your goldfish, including aminobutyric acid and somatostain!

If you wish to do a "fishless cycle" before you add fish it can help to seed beneficial bacteria, but your tank is still by no means "cycled".

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