How Do I Stop Ammonia From Building Up In My Aquarium?

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As a fish owner, I used to suffer from ammonia spikes. After a few times, I learned how to get rid of this toxic matter, but I still didn’t know how to prevent it from building up in the future. That is why I decided to dedicate an entire article to this topic.

Follow these steps to stop ammonia from building up:

  • Introduce nitrifying bacteria via substrate or a filter from an older tank.
  • Change 30 percent of the water weekly.
  • Use water conditioners during the water changes.
  • Vacuum the substrate to eliminate leftovers.
  • Avoid cleaning the filter too thoroughly. 
  • Feed your fish what they consume within two minutes.
  • Introduce live plants to your fish tank.

As we move forward, I will elaborate on the techniques that can prevent ammonia from building up in your tank. I will also include an incredible video showing how to vacuum the substrate correctly.

Still curious? Feel free to check my complete guide on aquarium ammonia, where I discussed what causes ammonia, how to get rid of it, what equipment to use, and much more.

How Do I Stop Ammonia From Building Up In My Aquarium?

Ammonia is not just a nuisance. At certain levels, it can kill every fish in your aquarium. Fortunately, there are many ways of reducing ammonia levels in poorly maintained tanks.

However, you are better off using the following steps to prevent the ammonia from spiking in the first place:

1. Introduce Nitrifying Bacteria

Established aquariums have beneficial bacteria that change toxic ammonia into nitrite and nitrate.[1] Nitrate is more appealing than ammonia or nitrite because the substance is harmless. 

But beneficial bacteria won’t manifest naturally. According to an article in the National Library of Medicine, you can use aquarium biofilters to cultivate nitrifying bacteria in significant numbers.[2]

You cannot prevent ammonia from building up without proper cycling. Aquariums have too many sources of ammonia, including fish waste, leftovers, and dead plants.

Fish will release ammonia through their gills.[3] Without nitrifying bacteria to process the ammonia; it will run amok.

Therefore, before taking any other action, you must cycle your tank. The process involves promoting the growth of nitrifying bacteria by adding ammonia sources.

Some people expedite this process by adding gravel from an established tank.[4] Aquarists do this because nitrifying bacteria will hide in the substrate. 

Therefore, adding gravel from an established tank to the substrate of a new tank will introduce the nitrifying bacteria from the old tank to the new one.

Filter media from an established tank will produce similar results. You can either take the filter or transfer the brown muck. 

Either way, the goal is to increase the population of nitrifying bacteria. A healthy population of nitrifying bacteria will keep the ammonia concentration under control.

One of my favorite products regarding this topic is the API Quick Start Nitrifying Bacteria (link to Amazon). Simply add 10 ml per 10 gallons of water when:

  • Starting a new aquarium.
  • Adding new fish to your tank.
  • Conducting a significant water change.
  • Changing the filter media.
  • Ammonia or nitrite are detected.

2. Conduct Routine Water Changes

You can combat high ammonia levels by performing a partial water change. First, removing 50 percent of the water will take a significant portion of the ammonia out. Secondly, adding new water will dilute the remaining ammonia. 

However, you don’t have to wait for the ammonia concentration to rise to perform a water change. New aquarists are advised to change roughly 30 percent of the water weekly.

Water changes can induce stress in fish because they alter the conditions in the aquarium, and fish hate change. Therefore, aquarists with sick and stressed fish are hesitant to perform regular water changes.

However, you can still change the water even when your fish are sick. The key is to perform smaller water changes more frequently. 

You can even perform daily water changes if they are small enough. Consistently changing the water will prevent the ammonia concentration from building up.

3. Use Water Conditioners Properly

Some aquarists only use water conditioners during emergencies when ammonia levels are too high. However, that is a mistake. 

Professional aquarists use conditioners whenever they change the water. Otherwise, the new water may introduce ammonia to the tank. 

Some beginners use de-chlorinators to purify tap water. This practice only makes sense in regions that use chlorine to disinfect tap water.

But if your local authorities prefer chloramine, the conditioner will remove the chlorine and leave the ammonia behind. 

If you don’t know anything about chloramine, you may not understand why ammonia levels increase after every water change. 

A decent conditioner will remove the chlorine and neutralize the ammonia in the new water. I personally use the Seachem Prime Conditioner (link to Amazon) each time I perform a water change. Simply add 1 ml for every 10 gallons of water.

4. Remove Dead Organic Matter

Have you cleaned the aquarium? A water change is not enough. It will remove some of the pollutants, but you cannot trust the practice to eliminate all the debris.

Don’t forget: fish produce waste that sinks into the substrate. Leftovers are the same. Any food the fish cannot eat will descend to the bottom. What do you think happens when that organic matter rots? It will produce ammonia. 

But you can prevent this outcome by vacuuming the bottom and removing any organic matter you see in the water, including fish. 

Some aquarists rely on creatures like shrimp and snails to clean the aquarium. But you cannot trust shrimp and snails to eat fish carcasses before they rot. 

This applies to dead plants as well. Make sure you remove them before they become a problem. You can apply this solution to tanks with high ammonia concentrations. 

You have to remove the dead organic matter before performing a water change to lower the ammonia. But you are better off taking action before ammonia becomes a nuisance.

  • For those of you who have never vacuumed the substrate, here is an excellent Youtube video that will show you how to do that:

5. Clean Your Filter Carefully

Clean the filter carefully. Organic matter can sit in the filter and rot, adding to the ammonia in the water. Therefore, you have every reason to clean the filter. 

However, you can’t clean this item too thoroughly. Keep in mind that a sizable population of nitrifying bacteria lives in the filter media.[5]

You don’t want to remove the bacteria. You should also keep the filter away from tap water. The chlorine in the tap water will kill the nitrifying bacteria.

You can, however, use the water from your tank to rinse the filter media. I usually do that every two months. 

6. Avoid Overfeeding Your Fish

Don’t overfeed your fish. Even though fish have tiny stomachs, they don’t know when to stop eating. This is a problem for beginners because they tend to feed their fish whenever the creatures demand food.

These individuals do not realize that fish will keep eating so long as you continue to feed them. They will also act hungry even when their tiny stomachs are full. 

You may see them hanging around at the surface, seemingly begging for food. But if you surrender to their demands, you will chock the water with leftovers. 

These are the same leftovers that eventually decompose to produce ammonia. You have to keep the fish on a strict diet. Feed them two times a day. 

Start by giving them food they can eat in a minute or two. You can either increase or decrease the volume depending on your observations.

You can also use an automatic feeder. These devices will feed the fish on time and in the right quantities. Avoiding overfeeding will prevent ammonia from accumulating by reducing the number of leftovers. 

7. Introduce A Few Live Plants

While ammonia is toxic for most aquarium creatures, plants actually benefit from it. They take advantage of the nitrogen component and use it to grow during photosynthesis.

Floating plants serve multiple purposes. First of all, they provide hiding spots for fish. Secondly, they will feed heavily on ammonia.[6]

Some other examples of plants that remove ammonia include Pothos, Amazon Sword, Hornwort, Amazon Frogbit, and Java Moss.[7]

Plants should work hand in hand with the methods above. But it would help if you didn’t rely solely on them to control the ammonia concentration.

Plants are also tricky because they produce ammonia when they die and decompose. That is why you have to keep an eye on them.

These signs typically indicate that your plants are dying (and produce ammonia in the meanwhile):[8]

  • The leaves will gradually turn brown or white.
  • The plants will disintegrate and melt.
  • You will notice tiny pinholes on their leaves.
  • the leaves will fall off.

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Getting rid of ammonia is pretty straightforward. All you need to do is perform a significant water change and use some detoxifiers.

However, preventing ammonia from building up is more challenging and even more crucial. Start by eliminating things that produce ammonia.

That includes rotten food found in the substrate and dead organisms. You should also introduce nitrifying bacteria that turn ammonia into nitrite via the nitrogen cycle.