How To Lower Ammonia Levels In Fish Tank | Aquascape Addiction

How To Lower Ammonia Levels In Fish Tank

Need to know how to lower ammonia levels in your fish tank? we cover the 7 best options, each covered in detail.

How To Lower Ammonia Levels In Fish Tank

If you have any kind of fish tank or aquarium at home, you will know exactly what we are talking about here. Ammonia is a huge problem is planted tanks as well as normal fish tanks too. In fact, it is highly poisonous to any and all living organisms in your fish tank. It will quickly poison, eat away at, and eventually kill all of the plant and fish life in your aquarium. So, we are here today to help you figure out how to lower ammonia levels in your fish tank.

This ammonia is actually created by the breaking down of uneaten food, it is present in fish waste, and old or rotting plants will produce it too. Ammonia is a substance that you definitely need to get rid of (Using a Neutral Regulator like this will help). There are bacteria which convert ammonia into nitrites, which is partially beneficial for your fish tank. However nitrites are almost as poisonous to your fish as ammonia, so this whole conversion thing really is not ideal.

How To Lower Ammonia Levels In Fish Tank: 7 Ways

Now that we have covered what is ammonia in a fish tank let's now look at 7 ways of reducing ammonia levels;

1. Changing The Water

One of the easiest, fastest, and most effective ways of decreasing ammonia levels in the water of your fish tank is to simply replace the old and contaminated water with fresh water. To be fair, regular partial water changes is something that you should be doing on a weekly basis anyway. If you see that there is too much ammonia in the water, you can always perform the partial water changes more often.

One way to know that you aren’t doing these water changes often enough, is when you do them and the substrate (we have reviewed some good substrates over at this article), when stirred up, causes cloudiness in the water. This is a sign that you aren’t doing the water changes often enough because there is clearly a lot of waste sunk in the substrate. Simply remove about 30 percent of the water with a scoop or small bucket, while being careful not to agitate the fish or destroy plant life.

Put the same amount of fresh water in a bucket with some dechlorinating agents, let it sit for a few hours, make sure the temperature is roughly the same as the current tank water, and slowly pour it back in. In terms of numbers, this process should realistically take drop ammonia levels by 30%, or even more if you change more water. Keep in mind, it is not recommended that you ever change more than 30% of the water at once, or else you are putting the health of your fish at serious risk.

2. Remove Waste & Unwanted Organic Matter

Since rotting food, fish waste, and old plants can all cause ammonia, another easy solution to your ammonia problem is to remove the things creating or releasing it. Of course you aren’t going to remove the fish from the tank, because they are the whole point of having an aquarium, but there are several other things that you can do for sure.

Use a scoop or gravel filter (this one is good) to clean the substrate of any and all waste, uneaten food, and decaying plant matter. This will go a long way in lowering ammonia levels. Also, you can clean out the filter in your tank to make it more efficient at its job.

3. Less Feeding

If your fish leaves behind a lot of uneaten food, or if you realize that your fish produce an excessive quantity of waste when they shouldn’t be, it might be time to start feeding your fish less. Since both uneaten food and fish waste release ammonia, feeding them no more than the required amount may help to reduce ammonia levels.

4. Healthy Bacteria

Another thing that you can try doing in order to lower the ammonia levels in your fish tank is to introduce some healthy and beneficial bacteria into the equation. You can try adding some new fish into the water, adding gravel from an old tank, or get yourself a good filter with biological filtering, all of which will serve to add new bacteria into the water.

These bacteria will then break down the ammonia into nitrites, and eventually into nitrates. Both nitrites and nitrates are still harmful to your fish, but not nearly as much as ammonia.

5. Lowering The pH Level

When your water is basic, or higher up than 7.0 on the pH scale, ammonia tends to be present in higher concentrations because it does not break down as well is basic water. You can go to your local pet store and buy chemical pH adjusters to lower the pH levels in your fish tank. Just beware that your fish do have a specific pH range which they need to live, so that is something you will need to take into consideration.

Lowering the pH levels in your fish tank will not actually remove the ammonia from the water, but it will make it less potent and dangerous to your fish. You can actually also try adding new gravel into the tank as opposed to coral or sand. Coral and sand will release calcium into the water, which will in turn cause a rise in pH levels.

6. More Aeration

Having a lack of aeration in the water is bad not only for your fish as they try to breathe, but also because it allows ammonia to stay present in the water much easier. Ammonia is a dissolved gas, so a lack of aeration can make it stay in the water.

On the other hand, increasing the aeration will increase the rate at which the ammonia diffuses into the air above the water, thus decreasing the levels of it in the fish tank. The only way to really do this is by buying an air pump.

7. Neutralizing Drops

The final thing that you can do in order to lower ammonia levels in your fish tank is to use neutralizing drops. These will not actually remove the ammonia from the water, but they will render its toxic effects non-existent.

Signs Of High Ammonia Levels In Fish Tank

There are a few common signs to look out for such as;

  • Appetite loss
  • Gills inflamed (pink around gills)
  • Eyes inflamed
  • Labored breathing
  • Fish surfacing to the top more than normal

If you are in doubt then you should definitely do a test asap, you can either use test strips or a liquid test kit (we think liquid ones are better personally).


Just remember that ammonia, even in the smallest of quantities, can end up making your fish sick and killing them very quickly so it's important to know not only how to identify but also how to get rid of ammonia which hopefully we have helped you to do so. It is important to test your water for ammonia on a regular basis, and if there is too much of it, use any or all of the above methods to rectify the situation.