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What to do when your fish tank cycle stalled

If you are cycling your fish tank, then you may run into an issue where the cycle seems to have stalled.

To see how you can get the cycle moving again, you can take a look at this troubleshooting article from Aquarium Blueprints.

1. If this is the first time cycling a fish tank, then it is very important to note that it will take up to 8 weeks (if not more) to fully cycled the aquarium if you are starting from sqaure one.

So, if you are still early on in the cycling process, you may simply need to wait a couple of days to see any significant process being made.

2. If you are in the middle or late stages of the cycling process before it seemingly stalled, then make sure that you don’t have ammonia and/or nitrite levels beyond 5 ppm.

If you have too much ammonia and/or nitrites in your tank water, then it causes the cycling process to stop.

To dilute these two compounds from your tank water, you need to do a partial water change.

3. If you decide to do a water change when you are still cycling your tank, then you may have been stalling your cycle by using tap water without first adding an appropriate aquarium water conditioner.

For the uninformed, tap water is treated with chlorine and chloramine to make it safe for you to drink. However, these same chemical compounds will also end up killing the beneficial bacteria living inside your fish tank.

Therefore, we recommend using an aquarium water conditioner like Seachem Prime to instantly remove the chlorine and chloramine from your tap water.

4. If your test kit is showing that you have 0 ppm of ammonia and/or 0 ppm of nitrites even though your fish tank hasn’t done cycling, then the lack of these nitrogen compounds may be causing your cycle to stall.

In this case, you simply need to add more ammonia so that you can feed and eventually grow your beneficial bacterial colonies.

5. You should also make sure that you have enough surface area in your tank. Most of the bacteria colonies will settle in the substrate of your tank as well as the compartments of your filter.

So, if you don’t have a substrate and/or filter, then you might want to consider adding this equipment to your fish tank if the cycling process keeps getting stuck.

6. If your fish tank cycle is still stalled, then one last solution you can try is to add more live bacteria to your fish tank.

If know someone with a cycled fish tank, then you can temporary borrow one of their filter media sponges and drop it in your tank. The beneficial bacteria living on the sponges will eventually establish themselves in your aquarium.

There are also several live bacteria products, such as the Seachem Aquavitro Seed and Seachem Stability, that will quickly increase the beneficial bacteria population in your tank.

By adding more bacteria, you should be able to kick start your stalled cycle.

To see what the major differences are between the aforementioned Seachem Aquavitro Seed and Seachem Stability, you can take a look at this versus article.