How Do You Add Nitrates To Aquaponics? (Easy Way)

I’ve been doing aquaponics for years, and I’m always looking for new ways to improve my system. Recently, I read about how you can add nitrates to your aquaponics system with these methods:

How do you manipulate nitrate levels in aquaponics with fish
Main Takeaways
Nitrate is an essential nutrient for plant growth in aquaponics
Fish waste provides a source of nitrate for the plants
Adding too much nitrate can be harmful to the fish
Nitrate can be added to the system through several methods
These methods include adding fish food, worm castings, or nitrate supplements
Monitoring nitrate levels is important for maintaining a healthy system

Add Nitrogen Rich Plant Foods

Plants use nitrogen to make the proteins they need to grow, so it’s essential that your plants are getting enough of this nutrient. 

You can provide your aquaponic system with nitrates in a variety of ways, but the simplest is to add plant foods that are rich in nitrates.

Here’s a list of some common nitrogen rich plant foods:

Grass clippings – grass clippings contain about 10% nitrogen by weight, which means you’ll need quite a bit of grass clippings if you want them to contribute significant amounts of nitrates for your fish and plants. 

If you have access to greenhouses or gardens that would allow for surplus grass clipping collection (or even just some grass on your lawn), then consider collecting these and adding them directly into the water column for both fish and plants!

Seaweed – seaweed contains about 2-3% nitrogen by weight and has been used as fertilizer for centuries because it is so effective at providing nutrients like potassium, phosphorus and micronutrients while also having natural anti-fungal properties which help prevent disease outbreaks or parasites within an aquaponics system

Aquaponics is a fascinating way to grow your own vegetables and fish while maintaining a sustainable system. Our complete step-by-step guide can help you get started on building and managing your own aquaponic garden with ease

Maintain pH Level

Another important aspect of maintaining your system is to maintain the pH level. This is a measure of how acidic or alkaline your water is, which tells you if it’s best for fish, plants or both. 

Ideally, you want a pH level between 6.5 and 7.5—this means that there are equal amounts of hydrogen ions (acidic) and hydroxide ions (basic).

Hydrogen ions increase when ammonia levels build up in an aquaponics system. If these levels get too high, they can harm fish and plants alike by burning their gills and leaves respectively; on the other hand, if there aren’t enough hydrogen ions present in the water then nutrients won’t be absorbed properly by either party involved in your aquaponics system

Methods to Maintain pH Level in Aquaponic Systems

Add nutrientsAdding limestone or crushed shells can help raise pH levels in your aquaponic system.
Acidifying agentsMuriatic acid or phosphoric acid can be used to lower pH levels in your aquaponic system. Be sure to use acidifying agents with caution and in small doses.
Carbonate supplementsCarbonate supplements can be mixed with the water in the system to increase pH levels.
Monitor pHRegularly monitoring the pH levels in your aquaponic system ensures that adjustments can be made quickly, preventing significant fluctuations.
Water changesSometimes, large water changes are the most effective way to restore the pH balance in your aquaponic system. Be sure to monitor pH levels after any water changes.

Use Fish Food

The first thing you need to know about feeding your fish is that they won’t be able to eat everything in a few minutes. 

You’ll have to feed them sparingly, only enough to make sure they are getting all the nutrients they need.

The second thing you need to know is how often and how much food your fish should get. Fish should be fed at least twice a day, with some kind of high protein food (like krill or other fish flakes) every time they eat. 

The amount of food depends on the size of your pond and how much water it holds; if you’re using a smaller pond, then just divide whatever amount of food I suggest by 10-20%. 

Finally, make sure not too much goes into their mouths at once—if there’s any spillage from their mouth when eating it’ll just pollute the water with waste!

Are you curious about what kind of vegetables you can grow in your aquaponic system? Our guide on what vegetables can be grown in aquaponics can provide you with the answers! From lettuce to tomatoes, you’ll be able to grow a variety of produce to suit your tastes

Manure Tea

Making manure tea is easy. You can use any animal, but for the sake of simplicity we’ll just stick with cow poop here.

Put your poo in a container large enough to hold it all, and add water until all the poop is covered. Try not to use too much water because this will dilute the nutrients that are being extracted from it and make them less effective in your plants’ soil.

Cover with some sort of lid or cloth just something that will keep bugs out and let gases escape while still allowing air to flow through. 

Lidless containers are okay if you want an extra strong brew! Just be sure there’s no sunlight getting inside (this will kill bacteria). 

If you’re using a lid, put holes in it so gases can escape as they ferment into carbon dioxide (look up how many holes depending on how big they are). 

If there’s no lid at all, cover loosely every few days so molds don’t grow on top; otherwise leave uncovered during fermentation period only after ensuring there are no pests inside or around container itself!

Molasses Tea

Molasses tea is an excellent source of nitrates that you can use to fertilize your plants. To make a batch, put 1 cup of molasses in a saucepan and slowly add 2 gallons of water while stirring continuously. 

Bring the mixture to a boil, then allow it to cool at room temperature for 24 hours before adding it to your fish tank or hydroponic system. 

Once added, you should see an increase in nitrate levels within 2 weeks.

Molasses tea works well with all types of plants except for tomatoes and eggplants because these vegetables are sensitive to high amounts of potassium (which molasses contains). 

You can use molasses as often as once per week during the first year after planting seeds or transplanting seedlings into larger pots; after that initial growing period has ended, start applying at least once every two weeks until harvest time approaches (when applying molasses becomes unnecessary).

If you’re unfamiliar with aquaponics or want to learn more about how it works, our guide on what is an aquaponics system and how do they work is a great place to start. Understand the basics of how plants and fish are grown together in a symbiotic relationship.

Use Fish Poop

You can use fish poop to add nutrients to your aquaponics system. Fish poop is high in nitrogen, so it’s a great addition for plants that need this nutrient. If you have a small amount of fish, just collect the poo out of the tank and throw it into your plants’ water supply.

If you have a lot of fish and want to keep them healthy and happy, consider setting up some sort of filtration system that will separate their waste from their water so they can still swim around while keeping things clean. 

Then, just dump in their discarded poo as well! It’s really quite simple just make sure not too much gets washed away during cleaning times because you don’t want things getting too dirty or smelly out there before they’re ready for harvest (or before they’re ready).

Compost Tea

Compost tea is made from compost. It’s a liquid fertilizer that contains high concentrations of beneficial microorganisms, which are great at breaking down organic matter and releasing nutrients into the soil.

Compost tea can be applied to plants either as a foliar spray (directly spraying the plant’s leaves) or as a soil drench (spraying the ground around your plants). 

If you’re using this method to help control diseases in your garden, make sure to spray both sides of the leaves so that it gets into all parts of the plant.

Ready to build your own aquaponic garden but not sure where to start? Our guide on how do you make an aquaponic garden-requirements can provide you with a checklist of everything you need to build your own self-sustaining system at home

Use Worm Manure

Worms are a great source of nutrients, and they can be used in many ways. Worm compost or worm castings are great sources of nitrates. 

You can purchase them online or at your local garden center, but if you have some worms already, this is an easy way to get more fertilizer!

Worms are easy to raise and maintain by feeding them food scraps (like vegetable waste) that would otherwise go in the trash. 

They can be collected and harvested when needed for composting or fertilizer production – or kept indoors as pets!

Get an A.I.R.Ponic system

If you’re looking for a way to add nitrates to your aquaponics system, an A.I.R.Ponic system is a great option. A.I.R.Ponics use the power of earthworms to process food waste into compost, which can then be added directly into your fish tank or grow beds for fertilizer that will increase plant growth and decrease nutrient levels in your water (which helps prevent algae outbreaks).

Aerobic digestion takes place when bacteria and other microorganisms break down organic materials like food waste at a rapid rate, producing both heat and carbon dioxide as byproducts (thus the “aerobic” part). 

The resulting compost can be used as fertilizer or mixed with potting soil before planting seeds or seedlings; if you’re using it on indoor plants indoors but want something with more nutrients than commercial potting mixes provide for outdoor gardens, this may be just what you need!

Comparison of A.I.R.Ponic Systems

System NameDescriptionFeatures
A.I.R.Ponic TowerA vertical growing system that utilizes an automated recirculating nutrient system to grow plants. The water is oxygenated by a constant flow of air.Can be used indoors and outdoors, Tower design maximizes the use of space, Water-efficient system, Can grow a variety of plants
A.I.R.Ponic Bucket SystemA hydroponic system that uses a constant airflow to aerate the nutrient solution in the water tank, providing optimal conditions for plant growth.Easy to set up and use, Low-cost system, Compact design is ideal for small indoor spaces, Can grow a variety of plants.
Commercial-Scale A.I.R.Ponic SystemA commercial-scale hydroponic system that utilizes a recirculating nutrient system to grow plants. Oxygen is introduced into the water using a proprietary system.Ideal for large-scale commercial use, High-yield production of plants, Requires a larger investment but offers high returns
A.I.R.Ponic DIY SystemA Do-It-Yourself high-pressure aeroponic system that is modular, scalable, and customizable according to the user’s needs.High yield production of plants, Completely customizable system, Low water and energy consumption, Can be used indoors or outdoors

Nitrates are an essential component of a healthy aquaponic system. Our guide on how do you add nitrates to aquaponics explores easy and efficient ways to add nitrates to your system and keep your plants and fish thriving.

Free Range Chickens (chicken poop)

One of the best sources of nitrogen is chicken manure. This is because chickens are omnivores, meaning they eat both plants and animals. 

They also have a more complex digestive system than many other animals (including humans), which makes their manure an excellent source of nutrients for your aquaponics system.

However, you must make sure that you’re getting it from free range chickens or other non-factory farmed animals.

 If you use factory farm chicken poop, it will be full of antibiotics and possibly E. coli bacteria as well! 

Be sure to compost your chicken manure before adding it to your aquaponics system so that these harmful chemicals break down first—otherwise they could end up in our food supply!

Stop Overfeeding Your Fish

One of the biggest mistakes that new fish farmers make is overfeeding their fish. When you overfeed your fish, they will release more ammonia into the water than can be processed by the bacteria. 

This causes an imbalance in your system and makes it harder for you to maintain a healthy balance between nitrates and ammonia.

You should feed your fish no more than they can eat in 2 minutes and no more than half of what they would normally eat in 4 hours. If there are leftovers after this time frame, remove them from the tank before adding any additional food! 

The best way to determine how much food is appropriate for each species is through trial and error so play around with how much you offer until you find what works best for each species of animal within your aquaponic system!

Tips to Avoid Overfeeding Fish in Aquaponics

Monitor fish behaviorIf fish are constantly swimming to the surface of the water and begging for food, it’s a sign they may be overfed.
Use a timerSet a specific feeding schedule and use a timer to ensure that fish are fed the correct amount of food.
Feed smaller quantitiesOnly give fish the amount of food they can consume within a few minutes and adjust as needed.
Keep track of feedingKeep a log of when and how much fish are being fed to ensure that they’re not overfed over time.
Use fish food with less proteinHigh protein fish food can increase fish metabolism which can, in turn, increase waste and put strain on the aquaponic system. Switch to fish food with less protein to avoid this issue.


In conclusion, adding nitrates to your aquaponics system is a great way to keep it healthy and thriving. 

However, you should be careful not to overdo it because too much nitrates can cause problems for your plants and fish.

Further Reading

Here are some additional resources you can use to learn more about aquaponics:

Aquaponics: The Complete Step-by-Step Guide: A comprehensive guide to aquaponics, covering everything from system setup to fish and plant selection.

How Often Do You Have to Change Water in Aquaponics?: This article explains how often you should change the water in your aquaponics system to maintain a healthy environment for your fish and plants.

What Vegetables Can be Grown in Aquaponics?: A list of vegetables that can be grown successfully in an aquaponics system.

How Much Does an Aquaponics System Cost?: An overview of the costs associated with setting up an aquaponics system, including equipment, fish, and plants.

How Do You Add Nitrates to Aquaponics? Easy Way: This article explains the different ways to add nitrates to your aquaponics system to promote healthy plant growth.

The Role of Nitrate in Aquaponics Systems: An in-depth explanation of the role of nitrate in aquaponics systems, and how it impacts plant growth.

Video Tutorial: Aquaponics for Beginners: A beginner-friendly video tutorial on how to set up and maintain an aquaponics system.


What is Aquaponics?

Aquaponics is a sustainable method of growing plants and fish together in a closed system. It involves using fish waste as fertilizer for plants, which in turn purify the water for the fish.

How does an Aquaponics System Work?

Aquaponics systems work by circulating water between fish tanks and plant grow beds. The fish produce waste, which is converted into nutrients by bacteria in the water. The nutrient-rich water is then pumped to the plants, which absorb the nutrients and purify the water for the fish.

What are the Benefits of Aquaponics?

Aquaponics offers several benefits over traditional farming methods, including:

  • Reduced water use
  • Higher crop yields
  • Fewer pests and diseases
  • Minimal environmental impact

What Types of Fish Can be Used in Aquaponics?

Several types of fish can be used in aquaponics, including tilapia, trout, catfish, and perch. It’s important to choose a fish species that is well-suited to the climate and water conditions in your area.

What Vegetables Can be Grown in Aquaponics?

A wide variety of vegetables can be grown successfully in aquaponics, including lettuce, kale, spinach, tomatoes, cucumbers, and peppers. The type of vegetables you choose will depend on the size of your system and the conditions in your area.