Best Aquarium Starter Bacteria Supplements

Ever bought a new tank with plants, substrates, and a few beginner fish to see them fall to their demise in a week?

It happens due to the absence of beneficial bacteria in your tank. Starting a new aquarium requires introducing bacteria, such as Nitrobactor and Nitrosomonas, and helping them colonize your filter media and substrate. These bacteria colonies help break down the ammonia, produced by feces and food waste into less harmful nitrate and nitrite. 

Although professional aquarists prefer to introduce them naturally, the process may take at least a few weeks. For eager aquarists like yourself, aquarium starter bacteria supplements are the best alternatives.

In this article, we’ll go through the best bacteria supplements that will help you jump-start your new aquarium. 

9 Best Aquarium Starter Bacteria Supplements




Available in 4 volumes, API QUICK START Freshwater and Saltwater Aquarium Nitrifying Bacteria is a beneficial bacteria additive that helps to quickly cycle new aquariums and eliminate harmful ammonia and nitrite. It contains live nitrifying bacteria that immediately start working to convert fish waste into non-toxic byproducts. This helps to prevent new tank syndrome and keep your fish healthy. 

Key Features

  • Allows Immediate Addition of Fish

API Quick Start works rapidly, and the live bacteria start cycling your tank immediately. You can add fish to your tank after a few days of adding the bacteria supplement. 

  • Prevents New Tank Syndrome

New tank syndrome is caused by built-up toxic compounds and immature filter media. This bacteria supplement prevents it from happening from the start. 

  • Helps Quickly Cycle After Restart

Not only the new aquariums, you can add API Quick Start after restarting your aquarium. This includes replacement of filter media, substrate deep cleaning, and 100% water change. 

  • Usable for Both Saltwater and Freshwater Aquariums

This bacteria supplement includes bacteria strains that work for both saltwater and freshwater aquariums. 


  • Very effective at eliminating ammonia and nitrite. It does what it says. 
  • Easy to use. The instructions on the bottle are enough to sustain your new aquarium. 


  • It might take a few days to start working with a normal dose. 
  • The bottle is smaller than it looks.

2. Fluval Cycle Biological Enhancer

Fluval Cycle Biological Enhancer


Treating 500 gallons of water, Fluval Cycle Biological Enhancer is a good option for aquarists who need to establish or maintain the nitrogen cycle in their aquariums. It is easy to use and affordable, and it helps promote a healthy aquarium environment. It also claims to add fish immediately. But, we recommend routine usage for a few weeks before introducing fish. 

Key Features

  • Contains Live, Beneficial Bacteria

Fluval Cycle contains live beneficial bacteria that help keep your aquarium water clean and clear. It also helps when restarting your aquarium. 

  • Helps Eliminate Toxic Ammonia and Nitrite

This bacteria supplement starts inoculating immediately and helps remove toxic ammonia and nitrite from the water. 

  • Safe for Saltwater and Freshwater Applications

Both freshwater and saltwater bacteria strains are present in the supplement to help hobbyists with multiple aquariums. 

  • Promotes Healthy Growth and Reproduction

Regular application of the Fluval Cycle helps exclude harmful pathogens from establishing in the tank—promoting growth and reproduction. 


  • Pretty cost-effective and easy to use. 
  • Cycles the tank within a few days of proper usage. 


  • Clouds aquarium water temporarily after usage. However, it’s not very abnormal to get cloudy water during cycling. 

Also Read: Nano Reef: 10 Steps For A Quality Setup

3. Aqueon Pure Live Beneficial Bacteria

Aqueon Pure Live Beneficial Bacteria


Produced in ball forms and packaged in 12 balls each, a pack of Aqueon Pure can cycle up to 240 gallons of water (Each ball can cycle 10 gallons). Similar to most good starter bacteria supplements, it also can’t be overdosed, and a weekly dosing routine should minimize the maintenance frequency.  

Key Features

  • Easy to Use Bio Balls

The unique approach to bio balls helps beginner aquarists start new aquariums more easily. Just drop them into the tank and wait for it to start working. 

  • Live beneficial Bacteria and Enzymes

The bio balls contain beneficial bacteria for nitrification and enzymes to promote overall well-being. The enzymes help break down organic sludge. 

  • Safer for Fish Than Fish-In Cycling

Bacteria supplements are generally safer for fish than subjecting them to a fish-in cycling process. Bio balls are similarly humane and safe.

  • Usable in Freshwater Aquariums

These bio balls are specifically made for freshwater aquariums and can be used regularly without needing to worry about overdosing. 


  • Easy to use and dose. The bio balls are quite easy to handle. 
  • Works pretty quickly and effectively. 


  • Sometimes the balls don’t dissolve completely. 
  • It can be expensive for larger aquariums. 

4. Seachem Stability

Seachem Stability


Made for both freshwater and marine aquariums, the Seachem Stability comes in 8-ounce bottles in liquid form. It contains beneficial nitrifying bacteria that help aquarists easily and quickly cycle their new tanks. It’s particularly useful for breeders who add multiple new tanks every week. 

Key Features

  • Blend of Aerobic, Anaerobic, and Facultative Bacteria

The Seachem Stability takes care of every beneficial bacteria that you can find in healthy tanks. Aerobic bacteria for filter media, anaerobic bacteria for substrates, and facultative bacteria for occasional usage. 

  • Reduces Risk of New Tank Syndrome

It keeps fish and aquatic creatures safe by creating a healthy ecosystem in the aquarium and reducing the risk of new tank syndrome in fish. 

  • Doesn’t Produce Hydrogen Sulfide

The included bacteria aren’t sulfide fixing and reduce the risk of producing hydrogen sulfide and gas pockets in the substrate.

  • No Risk of Overdosing

The non-toxic formula of Sealchem Stability ensures that no overdosing issues occur even after using it regularly. 


  • Safe for fish, invertebrates, and plants
  • Easy-to-use liquid solution


  • Causes initial cloudiness in the water
  • It has a strong odor

Also Read: Blue Ram Cichlid: Complete Guide To Care, Breeding, Tank Size And Disease

5. Fritz Aquatics FritzZyme 7

Fritz Aquatics FritzZyme 7


Made exclusively from freshwater aquariums and claims to be able to instantly cycle your aquarium, Fritz Aquatics FritZyme 7 comes in 3 sizes suitable for aquariums of different volumes. It also eliminates the new tank syndrome and may be used after water changes and aggressive cleaning. 

Key Features

  • Contains Freshwater Specific Live Nitrifying Bacteria

FritzZyme 7 only contains freshwater-specific nitrifying bacteria that help colonize them in your aquarium. It means higher concentration and faster introduction of livestock. 

  • Reduces Aquarium Cycle Time

This starter bacteria supplement reduces nitrogen cycle time to a great extent by introducing live beneficial bacteria into the water. 

  • Long Shelf Life for Repeated Usage

Thanks to its long-term stability, you don’t need to refrigerate FritzZyme 7 for repeated usage. It works pretty well in normal conditions.  

  • Reduces New Tank Syndrome

This product reduces new tank syndrome and helps fish and other creatures survive their first few weeks without any discomfort. 


  • Easy to use liquid solution. 
  • Effectively and rapidly reduces ammonia and nitrite


  • May not work for saltwater aquariums

6. Brightwell Aquatics MicroBacter7

Brightwell Aquatics MicroBacter7


Vet-tested and recommended, Brightwell Aquatics MicroBacter 7 comes in variations ranging from 125ML to up to 20L packages. This Aquarium starter bacteria supplement helps break down organic waste, enhances water quality, and ensures the establishment of healthy and beneficial bacteria colonies in your aquarium. 

Key Features

  • Complex Aerobic and Non-Aerobic Microbes

A complete culture of aerobic and non-aerobic microbes is introduced through this product. It helps establish effective biological filtration in new tanks. 

  • Enhances the Rate of Nitrification and Denitrification

Even in older tanks, it can enhance the rate of nitrification and denitrification when required. Moreover, the potent bacteria colonies can take care of the ammonia spikes pretty well. 

  • Suitable for Saltwater and Freshwater Aquaria

Both freshwater and saltwater bacteria strains are present in the bottle. A single product solves most of your starter aquarium issues. 

  • Reduces Phosphates

In addition to nitrification and denitrification, it also helps reduce organic carbon and phosphate from the tank. 


  • Rapidly reduces carbon, ammonia, nitrite, and phosphate.
  • Reduced hydrogen sulfide production.


  • May cause algae to bloom if overdosed.

Also Read: Why Is My Turtle Tank Water Cloudy? Top 6 Causes & Prevention

7. DrTim’s Eco-Balance Probiotic Solution

DrTim’s Eco-Balance Probiotic Solution


Made exclusively for freshwater habitats and available in multiple sizes, DrTim’s Eco-balance Probiotic Solution is a natural aquarium starter bacteria supplement that adds beneficial denitrifying bacteria to your aquarium. Owing to being relatively more potent, only a maximum of 10 ml per 10 gallons of water is recommended.  

Key Features

  • Introduces Natural Nitrifying bacteria

DrTim’s Eco-balance Solution introduces nitrifying bacteria sourced from natural environments to your aquarium. It helps break down toxic ammonia into less harmful nitrite and nitrate.  

  • Reduced New Tank Syndrome

Thanks to the rapid action of the bacteria supplement, new tank syndrome in fish is reduced. Your new fish will have a more welcoming environment in the tank. 

  • Reduces Algae Bloom

The inclusion of denitrifying bacteria also reduces algae bloom in the tank. You’ll potentially need to change water less frequently. 

  • Exclusive Strains for Freshwater Aquariums

The naturally sourced bacteria are exclusive to freshwater environments. The increased concentration makes the solution relatively more potent. 


  • Reduces harmful bacteria, including Vibrio. 
  • Promoted a healthy immune system.


  • Not suitable for saltwater aquariums.

8. PondWorx Pond Bacteria

PondWorx Pond Bacteria


Manufactured and packaged exclusively with ponds in mind, PondWorx Pond Bacteria keep your Koi pond and other large water fixtures clean and clear. While it may be used in smaller aquariums, its concentrated formulation may cause overdosing and oxygen loss issues in your tank. PondWorx comes in 4 different packaging sizes for different-sized ponds.

Key Features

  • Concentrated Formula

`1 gallon of PondWorx can instantly treat an acre area with an average depth of 4-6 feet. The higher concentration also helps build bacteria colonies faster. 

  • Safe for Koi and Aquatic Plants

The non-toxic formula doesn’t cause oxygen deficiency in the tank or allow algae bloom to happen. It’s safe for most freshwater pond fish, including koi and plants. 

  • Helps Break Down Organic Debris and Sludge

The enzymes present in the PondWorx help break down organic debris and sludge. It doesn’t allow protein or ammonia foam to accumulate. 

  • Easy to Use

No processing is required when using this product. Just pour in your pond and wait for a few days for the colonization to happen before introducing fish.


  • Improves water quality and clarity
  • Effective at breaking down muck and odors.


  • May cause foaming in your pond.
  • Doesn’t remove algae. 

9. Aquatop Forza Origin

Aquatop Forza Origin


Shelf-stable and rapidly working Aquatop Forza Origin helps you introduce fish and plants immediately to your tank without needing to go through a nitrogen cycle for weeks. It contains the right kinds of nitrifying bacteria that work for freshwater aquariums. Aquatop also claims to not have chemical fillers to keep the cost down. 

Key Features

  • Live Nitrifying Bacteria

Aquatop Forza Origin includes live nitrifying bacteria to help start your new aquarium. It rapidly starts creating beneficial bacteria colonies to help reduce the toxins in the tank. 

  • No Chemicals Added

No additional enzymes or chemicals are added to increase the concentration of the solution. 2 Oz of Forza Origin can treat aquariums up to 50 gallons.

  • For Freshwater Aquariums

Only the freshwater bacteria strains are involved in the nitrification process. You need to buy a different product if you have multiple types of aquariums. 

  • Reduces Ammonia and Nitrite

It effectively reduces ammonia and nitrite from the water. The nitrification and denitrification bacteria colonies help reduce the maintenance routine. 


  • Prevents New Tank Syndrome
  • Easy to use and quite affordable 


  • Can make your water cloudy, and the process may get a bit more delayed than advertised. 
  • Only for freshwater aquariums

Also Read: Torch Coral: Care Guide, Breeding, Tank Size, And Disease


Q: How do I start beneficial bacteria in my aquarium?

You can start beneficial bacteria in your aquarium in multiple ways. Among them, fishless cycling and using aquarium starter bacteria are the most potent methods. 

In fishless cycling, raw ammonia is dosed into the water for a few weeks to grow the nitrifying bacteria before introducing the fish. 

The bacteria supplements already include beneficial bacteria and other necessary enzymes to jump-start your new aquarium. You can introduce fish within a few days through this method.

Q: Do aquarium bacteria starters work?

Yes, more often than not, aquarium bacteria starters work pretty well. They include live nitrifying bacteria that start working rapidly and colonize filter media and substrates pretty quickly.

Q: What is the best bacteria for cycling aquariums?

We’ve compiled a list of the best aquarium starter bacteria you can get online. However, most products in this segment are similar in quality and work process.

The Bottom Line

We’ve discussed 9 best aquarium starter bacteria supplements that you can buy for your new aquarium. Hopefully, you’ll now be able to start your new aquarium within days and not in months with the natural fishless cycle method. 

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