What is fishless cycle?
In order to have sufficient amount of good bacteria in a new aquarium for the natural occurring aquarium nitrogen cycle, we must cycle aquarium or the fish will die. The methods to cycle aquariums without any fish are what we call fishless cycle. As the opposite to cycle aquarium with fish, fishless cycling is more humane because no fish will die in process. While there are more than one way to fishless cycling an aquarium, one of the fastest ways is to use pure ammonia.
There are two ways to do a fishless cycle.
A. Use pure ammonia.
B. Use fish food, or raw fish/shrimp.
In this article, we will cover the pure ammonia method. Another advantage of using pure ammonia to cycling a fish tank is to have the option of fully stock your tank with fish in one go after the cycle is done.
Whatever method you decide to use for cycling aquarium, you must set up an aquarium first. We will not get into details on how to set up an aquarium here.
Here is a quick list of the items you need.
1. A fish tank.
2. An aquarium filter.
3. An aquarium heater (if you will get tropical fish).
4. An air pump and its accessories.
5. An aquarium water conditioner.
6. A water test kit.
7. A source of pure ammonia.
Aside the necessary equipments to set up an aquarium, the only two other items here specifically for the purpose of fishless cycling are the water test kit and a source of ammonia.
The water test kit
The only way to know how much ammonia, nitrite and nitrate are there in the water is to test the water with a test kit. There are many different aquarium water test kits out there. One thing you must know is that liquid test kits are generally much more accurate than paper strip test kits. The latter is considered worthless for aquarium water testing by many people. The most commonly used water test kit with good reputation amongst aquarium hobbyists is the API Freshwater Master Kit. It is capable of testing ammonia, nitrite, nitrate, and PH. There is enough supply in one package for more than 150 tests. A single kit should be sufficient enough for you to complete aquarium cycling with still plenty to spare.
A source of ammonia
Some commercially available bottled ammonia can be used for fishless cycling. Whatever the source is, you must make sure there is no additive in the bottle. Check out the ingredients is essential. The only thing you need in the bottle is a form of ammonia compound and water. Some ammonia products have soap in them, which makes them completely useless for cycling a fish tank. One of the pure ammonia products I have used successfully is Ace Ammonia Janitorial Strength Formula. It is made of 90% water and 10% ammonia hydroxide. Another type of ammonia I have used is Ammonium Chloride Solution by Dr Tim’s Aquatics, while this is a much smaller bottle it is more than enough to cycle quite a few fish tanks.
Important things to know before you start the cycle –
Although the beneficial bacteria you want to grow in your new aquarium is waterborne, they can only grow in sufficient number by colonize surface areas within your fish tank. The most surface areas available in an aquarium are in the filter media. Therefore, cycling an aquarium is basically cycling the aquarium filter system, since it is where majority of your beneficial bacteria will be. You must make sure your filter system is turned on 24/7, and it must be rated high enough for your tank size or it will never have large enough surface areas in its filter media to have enough bacteria for taking care of the ammonia produced by your fish.
The Three Stages of Fishless cycle.
Stage One – “Growing” nitrosomonas
Define Stage: This is the stage where you will only find a reading on ammonia, while nitrite and nitrate both remain at 0ppm all the time. It requires the most patience, because it can be the longest stage with no sign of progress.
Goal: To get a reading on nitrite is what you should be after for this stage. By the time there is nitrite in the water, it means you already have large quantity of nitrosomonas to convert ammonia.
Tasks: After the tank is set up and everything (filter, heater, air pump) is running, you need to add some ammonia into the aquarium water. While there is no need for absolute accuracy when you drop ammonia, the general rule is not to add more than 6ppm. Too much ammonia can even be toxic to the good bacteria, and it will stall the aquarium cycling.
You need to test aquarium water every a few days for ammonia and nitrite. To make sure there is always ammonia in the water, and to check sign of nitrite to get an idea on how far the fish tank cycling has gone into. It can take up to 2~3 weeks before there is even a sign of nitrite.
Stage Two – “Growing” nitrobacter
Define stage: Once you get a reading of nitrite, it has entered stage two. Now the second group of beneficial bacteria nitrobacter will start to grow since there is finally food available to them. Nitrobacter would not grow during stage one because there was no nitrite available for them to feed on.
Goal: To get a reading on nitrate. You have to wait for nitrobacter to grow into sufficient number before there is a sign of nitrate, and during this stage this is exactly what you want.
Tasks: You will need to test the water daily to make sure there is always ammonia in the water, or the nitrosomonas grew during stage one will start to starve once all available ammonia is converted to nitrite. This stage is usually shorter than the second stage, but it can still take up to weeks before the next stage, where nitrate is finally showing up on test results.
Stage Three – Wait to reach a balance
Define Stage: As soon as you get a reading on nitrate, the fishless cycling has entered its final stage. Now there are a lot of both nitrosomonas and nitrobacter in the fish tank to convert both ammonia and nitrite.
Goal: To get 0ppm reading on both ammonia and nitrite. To achieve a balance between the two different species of good bacteria in order to convert all your daily dosage of ammonia into nitrate without a trace of ammonia and nitrite at the end of the day.
Tasks – You should continue to test the aquarium water on daily basis to make sure there is always ammonia to start each day with. You also must keep eyes on the nitrate concentration and PH at this point. During this stage, water buffer gets eaten away slowly and the PH might suddenly crash. When the PH is too acidic it can stall the fishless cycle. As soon as you see a drop in the PH, you should do a large water change to reduce the nitrate and to restore the water buffer as well as the PH.
You also must set your goal of how much ammonia you want your aquarium to be able to handle when it is completed. If you want 2ppm of ammonia being converted daily, you must make sure there is 2ppm ammonia in the water every day after you just gave a new dosage. Generally, 2ppm ammonia being converted daily can only ensure a light stock of fish. If you want to fully stock your tank at once, you need to aim for 5~6ppm ammonia being converted daily.
This stage should be fairly quick. It usually finishes within a week or so. Once you get a reading of 0ppm for both ammonia and nitrite a few days in a row while you still added ammonia 24 hours ago, the tank is fully cycled! You may add fish after one or more large partial water change to remove most of the nitrate.
Fishless cycling can be a slow and painful process for many people. Patience is required. The usual amount of time required to cycle a fish tank can be 6 weeks or more. Exactly time required can be vary case by case depend on many facts. There are certain useful tips to speed up fish tank cycling and cut the time required to as short as a week or less in some cases.