Bacteria In Aquaponics

Bacteria in aquaponics is often overlooked but if used properly it will increase the production of everything in your system.Bacteria in aquaponics

The next time you plant a new seedling or check on the fish in your aquaponics system, be sure to say a quick hello to the hardest working bacteria in your home. 

You may not be able to see or touch them, but the microscopic creatures in your aquaponic system are doing a very important job. 

By breaking down fish waste and converting it into nourishment for your fruits or vegetables. 

The bacteria in an aquaponics system provides a vital link between both plants and fish.


The Basic Aquaponics Cycle

  • The fish eat fish food 
  • The fish produce waste
  • Bacteria turns ammonia into nitrate
  • The plants absorb the nitrate
  • The plants grow and mature 
  • And the cycle continues


Bacteria in aquaponics

Without it, neither the fish nor the plants could survive; the relationship is symbiotic. 

By providing a reliable link between waste and nourishment, it’s the positive bacteria which enables the process to continue and ensures the health of your aquaponics system.

For this reason, it’s important not to underestimate the work of bacteria when establishing or maintaining an underwater ecosystem. 

Let’s take a look at what type of bacteria is best for aquaponics systems and how you can help it flourish.

Nitrifying bacteria- ammonia into nitrate

7.5-8.5 ph is best for bacteria to work (Nitrosomonas and Nitrobacter) but other bacteria work is lower ph so it is not super important.


Getting to Grips with the Basics 

The bacteria in an aquaponic system are responsible for breaking down the fish waste and producing nutrients that the plants can use to grow.

With remarkable efficiency, this positive bacteria converts harmful ammonia into nitrite which can be absorbed as “food” via the plant’s roots. 

This is why, in a healthy aquaponics environment, there are hundreds of billions of these invisible organisms: across grow beds, on the pumps, in the protective slime coating the fish and on your hands every time you touch the water.

Taking the time to learn about these magnificent critters is the first step to creating a high functioning aquarium. 

So, where do they come from? How can you get some and what do they need to get started? 

Well, the good news is adding positive bacteria to an aquaponics system can be both cheap and easy. 

Consider what we’re told about the nature of bacteria when learning in school. It’s everywhere, all around us, all the time.

The bacteria you need is already present in your atmosphere, on your home’s surfaces, and on your own body. 

You’re expelling bacteria every time you take a breath. This bacteria remains inert until conditions change and align with its breeding requirements. 

Thus, to get the bacteria working for your aquaponics system, you’ve just got to give it the right temperature, food, and breeding environment.

While you can buy containers of water containing bacteria that are already feeding and propagating – to jumpstart your aquaponics project – don’t believe anybody who tells you they’re essential. 

They’re just a shortcut to an end result you can create for yourself.

Having beneficial bacteria in your pond will also help create a healthy system. The bacteria in the system will increase the nutrients which allow your plants to grow bigger and better.

What You Need to Do to Start Your Aquaponics System

The first lesson when creating an aquaponics system from scratch is patience. It takes time for the bacteria to begin breeding and exerting a regulating effect on the ecosystem in the tank. 

If you add the fish or plants too early, they’ll die because you haven’t established a reliable ecosystem before introducing them. 

For instance, the freshwater most people use to fill an aquarium is chlorinated (at some point) to remove bacteria before drinking.

It’s this bacteria you need. Therefore, hastily combining near sterile water with a bunch of healthy fish will quickly lead to a very unhealthy fish. 

Even with a reliable food source and compatibility with the water, the fish will die because there are no bacteria to break down their waste. 

In time, the water will become toxic (ammonia-rich) and the ecosystem will eventually fail. 

Without bacteria, there’s no balance, no regeneration, and no perpetuating life cycle.

The solution can appear contradictory to those who are new to aquaponics. The fish produce ammonia. 

Yet, too much ammonia is deadly to them. The bacteria need ammonia to feed on so they can negate this toxicity by turning the gas into plant food. 

So, ammonia is both dangerous and central to the life and health of the ecosystem. 

This is why most people use a process of monitored cycling to establish their aquaponics system. 

It involves adding small, controlled amounts of ammonia to an empty (fishless) tank in order to generate a viable ecosystem before introducing plants or fish.    

It’s not as complicated as it sounds. 

The true challenge for most people is patience. 

When you’re excited to get started, it’s tempting to rush the process and add the fish too early. 

The key to success is cycling with care and taking regular readings of the water to determine nutrient and bacteria levels. 

When both are optimal, you should be able to add your fish and plants and have them take over the process of producing (excreting), converting (breaking down) and resupplying (creating plant food).


Introducing the Ammonia

bacteria in aquaponics

There are various different ways to add ammonia to a tank and begin fishless cycling. By far the most reliable is pure ammonia. 

It contains only ammonia and water – without the colorants or perfumes common to commercial cleaning products – and can often be purchased from hardware stores.

If you can source pure ammonia, it’s the recommended method. 

However, some countries have strict rules on its sale, and it can be hard to find. 

Ammonium chloride (crystallized ammonia) is the next best option. 

If neither products are available, people have traditionally used ‘aged’ urine (stored for 3-4 weeks) or a small amount of decomposing material such as a dead fish or shrimp. 

Both of these methods have been known to work but they come with a risk of contamination from additional unwanted substances.

Add your ammonia source to an oxygenated (but fishless) tank in small, controlled amounts until you get a reading of ~5 ppm. 

Make a note of how much ammonia was needed to reach this specific reading. 

Then, add this exact amount once per day until the nitrate level in the water reaches 0.5 ppm. 

At this point, reduce the ammonia dose by half. 

Now, the goal is to reach a nitrate level of between 5-10 ppm and a nitrite level of zero. 

When you get both of these readings, the tank is ready for your fish.  

This optimal nitrate level means there are bacteria in the tank that is now robust enough to rebalance the ecosystem once your fish begin producing large amounts of waste. 

As it converts this waste into plant food, the water is also ready for its greenery. 

You should continue to measure ammonia levels in the tank after introducing fish and plants. 

Changes are often the earliest sign something is wrong in the water and your ecosystem is at risk.   

It’s hard to say exactly how long it will take for your tank to become ready for the fish. 

It depends on a number of factors such as; the size of the tank, external and internal temperatures, and the type of ammonia used. 

The optimal time to begin cycling is during the summer when external temperatures are higher. Bacteria loves warmth. 

The positive bacteria in your aquaponics system will propagate faster in summer than they will in winter.   


Maintaining a Healthy Aquaponics System 

As already mentioned, regular monitoring is very important. 

Keep a close eye on ammonia levels because, if they change, something has probably happened in the tank to cause an ecosystem imbalance. 

For instance, if a fish dies and is not removed from the tank quickly, the decomposition process will produce additional ammonia causing levels to rise and potentially become toxic.

Take regular nitrate readings as well. If the nitrate level gets too high, the balance between fish and plants may be imperfect. 

Ideally, you want to find the perfect number of fish for the volume of plants you have and vice versa. 

Rising nitrate levels are an early indication that there are too many fish and not enough plants converting their waste into non-toxic reusable components. 

Some people worry when their nitrate levels start to drop but this can be a positive sign providing the aquaponics system has no other issues. 

In a healthy tank, it indicates an optimal balance between fish and plants; the plants are converting the nitrate-based waste at the same pace the fish are producing it. 

It’s symbiosis in action.

It’s only possible because of the presence of positive bacteria in your ecosystem. 

This entire process – adding the ammonia, cycling, testing the water – is designed to ‘activate’ the bacteria already around you (on your skin, in the water, in the air, etc) and give it the right conditions to grow and flourish inside your tank. 

Without it, there is no food for the plants and no healthy, breathable water for the fish.

There you have it: the story of a symbiotic relationship between bacteria, fish, and plants. 

The story of a successful aquaponics system.

It might be weird but using worms in aquaponics can also add benefits. I have written a whole article on why you should add worms to your system here.

If you are interested and what to learn more about aquaponics, but don’t want to spend the time and money for a big system, a simple solution is a home aquaponic system.

Home aquaponic systems are small fish tanks with built-in grow beds where you can choose to grow whatever you want. These home systems are cheap and allow you to experience aquaponics in the comfort of your home.

bacteria in aquaponics

My personal favorite and the best one I have used is the Back To The Roots aquaponic system. They are currently having a sale for over 30% OFF!