Something that you need to do before putting fish in a tank is to cycle the fish tank. This means that you allow beneficial bacteria to build up. Your fish tank needs to have beneficial bacteria to break down the ammonia created by fish waste.
These bacteria break ammonia down into nitrite, and then down into nitrate. Both ammonia and nitrite are toxic to fish, but nitrate is not really. This is a necessary process for all fish tanks. How to cycle a fish tank is exactly what we are going to teach you today.
How to Cycle a Fish Tank: Step by Step
Let’s go through the process of cycling a fish tank. It’s not very difficult, but it will take a bit of time and precision.
1. Set Up Your Tank
The first thing you need to do is to totally set up your fish tank. Here, you’re going to add the decorations, the gravel, the water, the filter, heater, and anything else that needs to be plugged in.
Remember, those beneficial bacteria need surfaces to hold onto. The biological filter media in your filter is one of the best, as are the gravel and the plants.
At this point, you want the water temperature to be somewhere around 70 to 75 degrees Fahrenheit. Beneficial bacteria grow best in these temperatures.
2. Test the pH of the Water
To allow these beneficial bacteria to grow quickly, they need to have an ideal pH level. The pH level of the water should be a neutral 7. Therefore, you need to use your pH test kit to test the water. If the pH is either lower or higher than 7, you will want to adjust it.
3. Add Ammonia to the Water
Yes, these beneficial bacteria are meant to breakdown ammonia into less harmful substances. However, these bacteria won’t start to appear in the water if there is no ammonia present. Therefore, you should take some basic ammonia and add it into the fish tank.
You want to ensure that the water has four parts per million of ammonia. This is for tanks over 40 gallons. If the tank has less than 40 gallons of water in it, go for two parts per million.
You now need to use an ammonia test kit to ensure that the water has the correct amount of ammonia in it. Keep in mind that anything over five parts per million can slow down or even stop this cycling process. You now need to leave the tank before the next week.
4. Add More Ammonia to the Water
On day eight, you are going to add about half of the amount of ammonia that you added on the first day. Those beneficial bacteria will starve if they don’t have ammonia to eat. Keep testing the ammonia levels in the water to ensure that it does not go above 4 parts per million.
You should now use your test kit to test for nitrite. After about the first week, those beneficial bacteria should have broken down a lot of the ammonia into nitrite. If you see that there is nitrite present in the water, then the cycling process is working. Let this go on for another week or so.
After about two weeks from adding the initial dose of ammonia, you should start to see both ammonia and nitrite levels dropping. At this point, you should see nitrate levels increasing. If nitrate levels are increasing, it means the beneficial bacteria are breaking down ammonia into nitrite, and then nitrites down into nitrates.
5. Continue the Process
Continue adding very small amounts of ammonia to the water on a daily basis for the next week. Once again, ensure that it does not go over four parts per million. Also, the doses that you add on a daily basis should be about half or slightly less than half of the initial dose.
After about three weeks since the initial ammonia dose, you should now have more than enough beneficial bacteria in the tank to break that ammonia down. At this point, you want to do daily testing for both ammonia and nitrite.
If both ammonia and nitrite levels are at zero after having added ammonia 24 hours earlier, it means that the cycle is complete. It means that the tank now has enough beneficial bacteria to quickly and effectively breakdown ammonia into nitrite, and then nitrate.
6. One Last Dose
Once you are at around four weeks, allow the nitrite and ammonia levels to reach zero. Once they reach zero, add a full dose of ammonia, as much as you did in the beginning. Go back to your tank in 24 hours and test for ammonia and nitrite. If both are at zero, then your fish tank is ready to go and is fully cycled.
Cycling Your Fish Tank
Remember folks, you absolutely need to cycle a fish tank before you add fish. If you fail to do so, chances are fairly large that your fish will die. If there are no beneficial bacteria to break down ammonia, that ammonia will poison your fish.
Aquarist & Writer 15+ Years