Cycling a New Aquarium

Cycling a New Aquarium: Getting Started

What is "Cycling"?
When setting up a new aquarium (whether freshwater or saltwater), you need to be aware of a process known as the Nitrogen Cycle, or as many hobbyists refer to it: "cycling". The Nitrogen Cycle is a cycle that all new aquariums must go through before they become suitable habitats for aquatic livestock. Cycling an aquarium typically takes between 2-8 weeks.

Why is Cycling a New Aquarium Important?
Unlike in nature, an aquarium is an enclosed habitat - all of the waste and detritus from your fish, other aquatic livestock, and fish food stays trapped inside the aquarium to decay, making the water toxic to inhabitants. The purpose of cycling a new aquarium is to establish beneficial "good" bacteria in the aquarium and filter media that will break down the waste and detritus in the aquarium, making the aquarium a safe and healthy environment for your livestock.

Stages of the Nitrogen Cycle:

1. First Stage
In the first stage of cycling a new tank, bacteria break down waste in the aquarium into Ammonia (*Ammonia is highly toxic to livestock).

2. Second Stage
In the second stage of the cycle, bacteria break down Ammonia into Nitrites (*Nitrites are highly toxic to livestock as well).

3. Final Stage
Lastly, bacteria break down Nitrites into Nitrates. While Nitrates are not as toxic to livestock as are Ammonia and Nitrites, in high quantities Nitrates are toxic as well. In order to reduce the level of Nitrates in the aquarium, regular partial water changes must be performed as part of routine maintenance.



How Will I Know When My Aquarium has Finished Cycling?
You should monitor the Nitrogen Cycle in your tank by testing the water for Ammonia, Nitrites, and Nitrates on a regular basis. When the Ammonia spikes in your aquarium, you will know the cycle has begun. Next, you should see that the Ammonia levels in the aquarium should drop to 0 ppm, and the level of Nitrites in your aquarium should spike. Then, you should see that the level of Nitrites in your aquarium should drop to 0 ppm, and the level of Nitrates in your aquarium should spike. At this point, you should begin performing partial routine water changes on the aquarium. When your Nitrates drop to less than 5 ppm, the cycle is completed, the beneficial bacteria has been established, and you can finally begin stocking your tank!

How Do I Cycle My Aquarium?
There are two methods to cycling a new aquarium: With Fish or Fishless.

1. Cycling With Fish
To begin with, while this is a popular method for cycling a new aquarium, I highly discourage it. Cycling a new aquarium with fish consists of triggering the cycle by adding cheap hardy fish to the aquarium. The waste from these fish will trigger the cycle. Fish that are often used for cycling include goldfish, "feeder" fish, and danios in freshwater aquariums, and damsels and chromis in saltwater aquariums. While this method works, it puts the fish under a lot of stress as they undergo the Nitrogen Cycle. Many fish will not survive the cycling process, and those that do may suffer from gill damage or diseases. IMO, cycling with fish is an unnecessarily cruel way to trigger the cycle.

2. A Fishless Cycle
There are several fishless options for cycling a new aquarium...

Method 1 - Fish Food:
You can trigger the Nitrogen Cycle simply by adding fish food to your aquarium.

Method 2 - Raw Shrimp or Fish:
By adding a raw shrimp or piece of raw fish to the tank you can trigger the cycle.

Method 3 - Use Gravel, Water, or Filter Media from Another Cycled Aquarium
This is a great way to start off a new aquarium. Use some gravel, water, and/or filter media from another already cycled tank.

Method 4 - Live Rock and Live Sand (Saltwater Aquariums ONLY)
Establishing beneficial bacteria colonies is especially important in saltwater aquariums. The majority of hobbyists use Live Rock (LR) and Live Sand (LS) to start cycles in saltwater aquaria. The LR and LS comes with beneficial bacteria that "seeds" your aquarium.

Method 5 - Add Ammonia
You can actually start the cycle by adding pure ammonia to your aquarium. You need to research how much ammonia should be added to your aquarium depending on the size of the aquarium.

Method 6 - Commercial Products
There are several commercial products on the market that claim to trigger and/or speed up the Nitrogen Cycle.

*While all of the above methods are viable, I encourage the more "natural" fishless options which would be Methods 1-4.

Another thing to mention is a lot of people freak out when their days old aquarium fogs/hazes in coloration. THIS IS OK! This is part of the cycle. It will clear on its own in a few days

If your established aquarium turns white/hazy/cloudy however, something is awry. Routine water changes will keep this from happening!

+1 Hazy water, a red tide or sewage-smell, and algal blooms are all common during cycling. Don't freak out. Just have patience.