Ammonia Removers for Fish Tanks

Maintaining a healthy aquarium environment is essential for the wellbeing and longevity of fish. Ammonia build-up is one of the biggest threats, and can quickly turn a thriving tank toxic. Choosing an effective ammonia remover is therefore critical.

This comprehensive guide will provide fishkeepers with everything they need to know about selecting, using and understanding ammonia removers for freshwater and marine aquariums.

What is Ammonia?

Ammonia (NH3) is a colorless, pungent gas highly soluble in water. It is the first nitrogenous waste product excreted by fish due to respiration and metabolic function.

In low levels, ammonia can be tolerated. However, in higher concentrations, it becomes extremely toxic. Exposure to excessive ammonia can result in:

  • Respiratory distress
  • Irritation of the skin, eyes and gills
  • Osmoregulatory dysfunction
  • Immune system suppression
  • Organ damage
  • Death

Ammonia levels above 0.02 ppm are considered unsafe. Anything above 0.6 ppm can be rapidly fatal.

Causes of Ammonia Build Up

Ammonia production is a normal part of the nitrogen cycle. Ammonia levels will spike in a newly established tank as the nitrogen cycle begins. Once the tank matures and beneficial bacteria colonies are established, ammonia is efficiently processed into nitrite and nitrate. However, ammonia can accumulate in any aquarium due to:

  • Overstocking – more fish produce more waste.
  • Overfeeding – excess food decays into ammonia.
  • Overcleaning – disrupting bacterial colonies.
  • Dead fish or plants – decompose into ammonia.
  • Immature tanks – the nitrogen cycle is not fully established.
  • Filter failure – beneficial bacteria die off.
  • pH fluctuations – affects toxicity of ammonia.
  • Temperature – higher temperatures increase ammonia toxicity.

How Ammonia Removers Work

Ammonia removers work by chemically detoxifying ammonia into a less harmful compound, or physically extracting it from the water column. Here are the main types of ammonia remover:

  • Ammonia Binding Agents – chemically bind and detoxify ammonia.
  • Zeolites – absorb and sequester ammonia.
  • Activated Carbon – adsorbs ammonia.
  • Algae Scrubbers – algae uptake ammonia.
  • Reverse Osmosis Systems – physically remove ammonia.
  • Protein Skimmers – generate foam that strips ammonia.
  • Biofiltration – beneficial bacteria convert ammonia.

Understanding how each works allows you to select the most appropriate for your aquarium.

Top Ammonia Removers Reviewed

With so many products on the market, choosing the right ammonia remover for your tank can be tricky. Here is an overview of some top performers:

Seachem Prime

Seachem Prime is one of the most popular and trusted ammonia removers. This concentrated conditioner instantly detoxifies ammonia, nitrite, and nitrate into safe compounds. It is very fast-acting, and a small daily dose can make a big difference in just a few hours.

Prime is safe for freshwater and marine tanks and can protect fish during tank cycling, water changes, and emergencies. It also dechlorinates and detoxifies chloramine, making tap water safe.


  • Extremely effective ammonia remover
  • Detoxifies other nitrogen compounds
  • Concentrated formula offers great value
  • It can also be used when transporting fish


  • It has a strong odor some find unpleasant

API Ammo-Lock

API Ammo-Lock is another ammonia binding agent that converts ammonia into ammonium, instantly detoxifying it. It is specially formulated for both freshwater and saltwater aquarium use.

A few drops per 10 gallons will remove low to moderate ammonia levels. For high concentrations, you may need to dose every 12 hours until levels come down. Ammo-Lock also helps detoxify nitrite and nitrate.


  • Affordable price
  • Specifically designed for aquarium use
  • Can be used with fish present


  • May not be strong enough for high ammonia spikes

Fritz Aquatics Ammonia Alert

Fritz Ammonia Alert uses zeolite minerals to absorb and sequester free ammonia molecules from the water column. The zeolite beads are contained in a mesh bag, which can be placed in a filter or hung in the aquarium.

Zeolite has a high cation exchange capacity, meaning it effectively adsorbs and traps ammonium ions. The beads also help buffer pH.


  • All-natural mineral product
  • Actively removes ammonia
  • Long lasting – beads change color when saturated
  • It can be reused by boiling and recharging


  • Only suitable for freshwater tanks
  • Can release ammonia back into the water if overloaded

Marineland Bio-Bag Filter Cartridge

These disposable filter cartridges from Marineland feature activated Carbon to adsorb impurities, paired with zeolite to tackle ammonia and odors. The lightweight bags are easily placed into any filter.

The zeolite beads sequester ammonia molecules while the Carbon removes discoloration and other dissolved organics. This combination helps clear cloudy water and creates a healthier environment.


  • Dual-action carbon and zeolite
  • Pre-filled cartridges are easy to use
  • Helps improve water clarity
  • Made for all Marineland filters


  • Activated Carbon can release absorbed organics back into water when spent
  • It needs replacing regularly before beads are completely saturated

Mars Fishcare BioSpira

BioSpira consists of highly concentrated nitrifying bacteria that rapidly establish colonies to accelerate the nitrogen cycle. These beneficial bacteria immediately begin breaking down toxic ammonia and converting it into nitrate.

Dosing new tanks with BioSpira allows the biological filtration to work fast enough to support fish immediately. It also helps reboot crashed cycles due to chlorine, antibiotics, or temperature shocks.


  • Contains live nitrifying bacteria
  • Quickly processes ammonia and nitrite
  • Allows immediate addition of fish
  • Helps cycle new tanks faster
  • Recovers lost bacterial colonies


  • Bacteria have a short shelf life
  • Only suitable for freshwater aquariums
  • More effective when combined with conditioners

Aquarium Co-Op Water Clarifier

Aquarium Co-Op Water Clarifier uses micron filtration pads to mechanically remove free floating particles and waste from the water, including toxic ammonia molecules.

The ultra-fine pads have a deep pore structure to trap micro-debris and impurities. They quickly help polish and clarify cloudy water caused by bacterial blooms or high ammonia levels.


  • Provides mechanical micron filtration
  • Traps microscopic waste, including ammonia
  • Clears up cloudy or hazy water
  • Pads are reusable – rinse and return


  • Will not remove ammonia already dissolved in water
  • It needs rinsing regularly as pores get blocked
  • It may become a secondary waste source

Fluval Ammonia Remover

Fluval Ammonia Remover is a chemical filter media containing ion-exchange resins to bind ammonia and remove it from freshwater aquariums selectively.

The small beads are packed into a mesh bag and placed into the filter. As water passes through, ammonium ions are attracted to the active sites on the resin. This reduces overall ammonia concentrations.


  • Chemically extracts ammonia
  • Media changes color when exhausted
  • Comes ready to install in mesh bags
  • Can also reduce odors


  • Not recommended for saltwater tanks
  • Resins can leach harmless salts into water
  • May release ammonia back into water if overloaded

Hagan API Ammo Chips

API Ammo Chips provides both chemical and biological filtration to manage ammonia waste. These tiny plastic beads contain zeolite to absorb ammonia, a nitrifying bacteria source.

The zeolite rapidly binds ammonia molecules in the water, while colonies of Nitrosomonas and Nitrobacter bacteria convert ammonia into nitrate. This dual-action biological and ion exchange process keeps levels low.


  • Combination of zeolite and live bacteria
  • Establishes fast biological filtration
  • Reduces ammonia, nitrite, and nitrate
  • Compact and portable for traveling


  • Bacteria take time to colonize and become effective
  • Zeolite can become saturated over time
  • Not recommended for saltwater

Tetra Cleaning Bacteria

Tetra Cleaning Bacteria is a nitrifying water conditioner that establishes populations of bacteria to metabolize ammonia and nitrite.

It contains Nitrosomonas, which oxidizes ammonia into nitrite, and Nitrospira species, which further breaks nitrite into less toxic nitrate. These bacteria colonies act as a biological filter to remove ammonia waste.

Regular use can reduce ammonia and nitrite levels while keeping tanks cleaner. It’s formulated for both freshwater and saltwater aquariums.


  • Establishes nitrifying bacteria to process ammonia
  • It also contains slime-eating heterotrophic bacteria
  • Safe for fish, plants, and biological filtration
  • Works in both freshwater and marine tanks


  • Effects can take 2-3 weeks as bacteria multiply
  • Works best when used regularly
  • It won’t manage high ammonia spikes on its own

Natural Ammonia Removers

In addition to commercial products, there are some natural and homemade options for removing ammonia from aquariums.

Live Plants

Introducing live aquarium plants can help absorb ammonia directly through their leave, stems and roots. Floating plants with access to atmospheric CO2 thrive best.

Some good options include:

  • Duckweed
  • Frogbit
  • Anacharis
  • Hornwort
  • Pothos

The more plants the better in terms of ammonia removal. Planted tanks help create a lush, healthy ecosystem.

Zeolite Media

Zeolite is a natural volcanic mineral with a porous structure and high cation exchange capacity. It adsorbs and traps ammonium ions, sequestering them from the water column.

Zeolite can be purchased as filter media such as bags of beads. For a cheap DIY option, clinoptilolite zeolite cat litter works well to absorb ammonia actively.

Mud and Peat

Adding bottled bacterial mud or peat to the substrate gives nitrifying bacteria a colonizing place. This establishes natural biological filtration in the tank bed.

Peat can also release tannins which help stabilize pH and reduce ammonia toxicity. Indian almond leaves perform a similar role.

Activating Carbon

While not specifically targeted at ammonia, activated Carbon is excellent for removing water impurities and preventing toxic build ups.

It can be used alone or paired with zeolite in media bags. Crushed into a coarse powder, Carbon makes great biological media for canister filters too.

Algae Scrubbers

Algae scrubbers allow algae growth on an inert surface. As the algae photosynthesize, it actively strips ammonia, nitrate and other nutrients from the water. Chaetomorpha is a good species to use.

The algae can be harvested regularly to export excess nutrients before it crashes and adds to the ammonia levels.

Understanding Ammonia Toxicity

It’s important to understand ammonia toxicity, test kits and warning signs to select and use ammonia removers effectively.

Facts About Ammonia Toxicity

  • Total ammonia refers to NH3 (toxic) + NH4+ (non-toxic). Only NH3-free ammonia causes harm.
  • NH4+ ammonium ions are much less toxic. Ammonia binding agents convert NH3 into NH4+.
  • pH, temperature and salinity affect the ratio of NH3 to NH4+. Higher pH and temp increase NH3 toxicity.
  • Ammonia is more toxic in soft, acidic water. Alkaline hard water offers more protection.
  • Due to higher pH, saltwater fish are more sensitive to ammonia than freshwater species.

Testing Ammonia Levels

Aquarium water should be tested regularly for total ammonia using a quality liquid test kit. Strips can be inaccurate. Ideal levels are 0-0.02 ppm.

Compare against the chart to interpret results:

  • 0-0.02 ppm – Safe
  • 0.02-0.2 ppm – Potentially harmful
  • 0.2-0.6 ppm – Dangerous
  • 0.6+ ppm – Fatal

Look for ammonia test kits which differentiate between NH3 and NH4+. This allows you to understand the true toxicity better.

Recognizing the Signs

If fish exhibit any of the following symptoms, test water immediately for high ammonia:

  • Gasping, rapid gill movement
  • Red or inflamed gills
  • Hanging at the surface or edges
  • Loss of appetite
  • Increased mucus production
  • Irritation, flicking or twitching
  • Sluggishness and lethargy

Cloudy or murky water can also be an indication of rising ammonia levels. Use visual cues and behavior changes to monitor tank health between tests.

FAQs About Ammonia Removers

Are ammonia removers safe for fish?

Yes, ammonia removers designed for aquarium use are non-toxic when used as directed. Seachem Prime is safe to use with fish present. However, always remove invertebrates like shrimp during treatment.

How long do ammonia removers last?

Depends on the product. Chemical/mineral types work instantly but may need re-dosing every 24-48 hours. Biological media takes 4-6 weeks to establish but offers long term reduction.

Can I use household ammonia removers?

No. Window cleaners and cooking products are unsafe. Only use aquarium-specific ammonia removers and water conditioners.

Should ammonia removers be used with water changes?

Yes, you can dose ammonia removers like Prime at each water change to detoxify any ammonia or chlorine released into the tank.

How do I remove ammonia without chemicals?

Natural methods like live plants, zeolite media, mud and algae provide biological filtration to reduce ammonia without chemicals.

Why is there still ammonia if I use removers?

It takes time to bring high levels down. Persistent ammonia indicates an underlying issue like overfeeding or dead fish. Keep dosing and fix the root problem.

Can too much ammonia remover hurt fish?

Overdosing certain products may negatively impact biological filtration or reduce oxygen. Always follow directions carefully and do not exceed recommendations.

How to Use Ammonia Removers Correctly

Follow this step-by-step guide to use ammonia removers safely and effectively:

Test Aquarium Water

Using a liquid test kit, check current ammonia levels. This provides a baseline to compare progress.

Calculate Correct Dosage

Read product instructions and calculate the dosage needed for the whole tank volume. Never guess or overdose.

Turn Off the Protein Skimmer (Saltwater Tanks)

Shut down the skimmer before adding medications to prevent foam overflow. Keep off for 30 minutes after dosing.

Remove Carbon Filters

Carbon can remove ammonia removers from water before they take effect. Temporarily take out carbon media like cartridges.

Add Ammonia Remover

Shake the bottle to mix. Carefully measure and add the correct amount to the tank. Avoid directly dosing on fish or invertebrates.

Re-test Levels After 12 Hours

Check if ammonia has decreased to safe levels. If not, repeat the correct dosage. Monitor daily until parameters normalize.

Do a Partial Water Change

Once ammonia nears 0 ppm, do a 20-30% water change to dilute concentrations further. Add conditioner.

Identify and Fix Underlying Issues

Determine what caused toxicity so it can be corrected. Rule out overcrowding, excess waste or dead organisms fouling water.

Allow Time for Biological Media to Establish

If using live bacteria, wait 4-6 weeks for full effect. Combine with other methods during this period if needed.

Rinse Mechanical Media Regularly

Clean removable cartridges, pads and meshes often to prevent trapped ammonia from leaching back into water.

Following Best Practice for Ammonia Control

In addition to using quality ammonia removers, adhere to these best practices for keeping aquarium ammonia at safe levels long term:

  • Maintain appropriate tank size and stocking density
  • Feed no more than what fish can consume in 3 minutes
  • Test water parameters weekly and top up buffers as needed
  • Clean filters monthly without destroying bacterial colonies
  • Limit lighting duration to control algae (8 hours max)
  • Remove dead fish, excess food and waste immediately
  • Perform 25% water changes every 2 weeks, or 10% weekly
  • Gravel vacuum substrate and decor when doing water changes
  • Ensure sufficient aeration and surface movement
  • Keep pH stable around 7.0-7.5
  • Maintain temperatures between 22-28°C (72-82°F)
  • Quarantine and treat sick fish in a separate tank
  • Use live plants and algae to uptake excess nutrients
  • Establish robust biological filtration to process waste
  • Work ammonia removers into your regular tank maintenance routine


Ammonia accumulation in home aquariums can become toxic, but can be avoided with proper tank management and appropriate ammonia removing products. Combining chemical, mechanical, and biological methods is recommended. Regular tank maintenance and monitoring of ammonia levels are crucial. Using quality removers can help maintain a safe, healthy environment, and fish thrive in clean, ammonia-free water. Researching, reviewing budgets, and choosing the right product can simplify maintenance and support aquarium success.