How Aquaponics Works

How Aquaponics Works – A Guide To Building Your Own System

What is Aquaponics?

AQUAPONICS IS AN INGENIOUS METHOD OF NATURAL FOOD PRODUCTION (fish & plant life) that Nature created and that you can now replicate at home…but on a much smaller scale of course.

The word Aquaponics is formed by the synthesizing of two words, aqua (water), and from the Greek ponos, or ponics (labor). When you combine the two, voila! Aquaponics. Simply put, ‘let the water do the work’ in a system that grows both fish and plants concurrently.

It is a natural process whereby the water containing the fish is pumped out and up into the plants above while the plants in turn, extract the nutrients, clean up the water, then return it to the fish tank in a seamless symbiotic relationship.

Here’s What You’ll Need to Get Started

You’ll need a fish tank or aquarium with a standard motorized pump, some PVC pipe and lights and of course, plants and fish. There may be a few more items but that’s the guts of it. We’ll get more into what kinds of fish and veggies are best to grow later in this article.

Whichever fish and plants you choose, the end result will be extremely healthy, pesticide-free vegetables and home-raised fish. This self-contained little eco system is naturally good for the environment as well. An added perk is that kids really love to interact with the entire process and they learn so much!

Oh, and you don’t have to live off the grid or be a Doomsday Prepper to enjoy this beautiful little system.

Which Aquaponic System is Best?

The concept is the same with them all. Your system choice should be based directly on what works best in your life style. Many systems are available for purchase on-line or if you’re the handyman type, with a few tools you can construct your own in an afternoon. A short list of available systems is laid out later in this article.

Aqua Facts: Aquaponics systems have been in use for thousands of years. The ancient Aztecs of Mexico made an entire city out of floating islands, and would grow squash and maize, raise cattle, and even live on the islands. Aquaponics have been used in the rice paddies of China and Thailand for centuries.

The Advantage of Aquaponics

Minimal Waste

Watering your garden–whether outdoor or hydroponically, requires a lot of water. However, with an Aquaponics system your water requirements never increase unless you expand the system.

Since there is already water circulating through the system, you only occasionally need to add a bit of water in order to accommodate for evaporation. Bottom line, the Aquaponics system can reduce your water usage by up to 90% over traditional gardening. For even less water usage you could go with a system like fogponics, but it’s much harder to scale a system like that.

Reduced Costs

Using less water means fewer costs to run your garden. Rather than spending a small fortune watering your garden during the dry periods, you can keep the aquaponics system running all year long.

More Efficient Growth

The better nutrients the plants get, the more effectively they grow. 

The fish tank water is high quality plant food and the continual circulation will keep your plants growing beautifully.

Let’s not forget the harvest. With an Aquaponics system you’ll have larger plants in less time.

Grow Anytime, Anywhere

A bonus of the Aquaponics system is it’s highly versatile and can be used to grow fruits, veggies, herbs, and all kinds of flowers.

Weather or Not

An Aquaponics system is impervious to weather conditions. Outdoors you worry the weather could harm your plants but thanks to the design of the Aquaponics system, you will be able to grow your plants indoors year-round.

Your favorite veggies will be growing strong and healthy while outside plants may be burning up or being pummeled by rain or hail.

Less Time-Consuming

Another advantage of the Aquaponics system is there’s never any weeding or feeding to do. No plant-eating garden pests to deal with either.

In addition, an Aquaponics system is designed to be user-friendly and easy to operate. Not to mention, low-maintenance. Once the system is up and running, it basically runs itself.

TIP: Be sure to monitor the quality of your water each day and as with any aquarium, have a back up plan (a small generator) in case the power goes out and the air pumps quit working. The plants will be okay but the fish can’t live too long without oxygen.

An Easy Way to Grow Organic Food

We all know that many food products claiming to be organic aren’t always. I mean, how do you know for sure?

Moreover, you can spend more on products claiming to be organic and get lower quality than regular vegetables grown using pesticides.

The only way you can be sure that the food you are consuming is 100% organic and chemical-free is to grow it yourself.

Benefits of Growing Plants in Your Home

It is proven that having plants in a room has a positive effect on people’s moods. They also add color and oxygen to a room.

Aquaponics offers you the possibility to grow your own organic vegetables in your home while at the same time use them for decoration.

This way you not only will enjoy the beauty of green plants in your home, but you will also save some money from having to purchase them.

Plants & Veggies from Aquaponics

You may wonder what type of vegetables you can grow using the Aquaponics system. Fruity vegetables like cucumbers, strawberries, tomatoes, squash, okra, pepper, melon; herbs like basil and oregano; different types of beans and peas as well as green leafy vegetables grow very well in this system. Plants whose fruits grow inside the ground however, like potatoes, sweet potatoes, onions, garlic and so on aren’t recommended for obvious reasons.

What will amaze you at harvest is the great taste your homegrown food will have. You will not believe that something so good can be grown in your garage or in your living room. If you want organic food make sure you purchase organic seeds so you know your harvests will be 100% organic.

The Best Fish for Aquaponics Systems

As to the fish, some people don’t raise fish to eat but merely to enjoy the beauty of them while also digging the low maintenance. If you plan on raising supper for some future night, figure on about 9 months from tank to skillet.

Choosing the Right Aquaponics Fish Species

There are a few things you need to take into account when choosing the species of fish for your garden:

  • Temperature — How cold or hot does it get where you live? Some fish can’t handle the cold, and others hate the heat
  • Home — Are you breeding them in a large fish tank, a DIY tank, or another type of system? Some fish don’t do well in certain environments
  • Companions — A few fish are very anti-social, and they will often end up killing off other fish in the tank. You want to find a fish that can play nice with others!
  • Grow Rate — The faster the fish grow, the faster you can eat them
  • Hardiness — Do your homework to find a fish best suited for your needs and environment

Top Aquaponics Fish to Consider


The Tilapia is a survivor. Not only can it withstand poor water conditions, but is a fast-growing fish that reproduces quickly. They grow to be fairly large with a light and delicious flavor. They also feed primarily on plant-based foods, so they’re perfect for adding to an Aquaponics system.

Because they are so often grown on commercial farms, there are places where you are not allowed to own and breed tilapia. For example, in California, you can only own tilapia in the six southernmost counties. Make sure to check with your local fish and wildlife agency before buying tilapia–it may help you avoid heavy fines.


While goldfish are not edible, they make a great addition to your Aquaponics system. If you feed them right, they will produce a lot of waste material–perfect for feeding the plants you are growing.

However, the high waste production means you have to keep a closer eye on the pH of the fish tank. In addition, you will need to ensure there is plant-cover in the tank if you want them to breed. Apparently, they are a shy fish.

The downside of goldfish is what to do with them after they’re grown. You can’t sell or eat them.


Few fish taste as good as a freshly caught trout. Trout have a delicious flavor that makes them the ideal fish to breed and raise.

Trout also contain a lot of bones so filleting is paramount.

Trout tend to grow very quickly and have an excellent conversion rate.

Bass, Perch, Crappies

These fish are all carnivorous fish, which means that you will need to feed them bugs, shrimp, and smaller fish. This makes feeding them a whole lot more expensive than the other fish on the list.

A word of caution: Some perch and crappies cannot be imported into the US or Canada. Be sure to check with your local Fish & Game Authority before purchasing them.


This Japanese fish is ideal for those who want to make their Aquaponics tank look colorful and beautiful! They are almost perfect for an Aquaponics system, as they have a long life span, eat primarily plant matter, and are very resistant to the parasites that commonly affect fish.

Koi are easily obtained and produce a lot of waste matter, which is perfect for the feeding of your plants.

While pretty to look at, Koi are not a fish you want to eat. Pretty much, show only.


Anyone living south of the Mason Dixon Line will tell you, a catfish is one of the biggest growing, best tasting fish you’ll ever eat.

This was only a short list. There are limitless fish to grow for food or show. Do some research.

Aquaponics vs. Hydroponics

Many people ask if Aquaponics and Hydroponics are the same. While they are related, they are separate growing systems.

Both systems rely on water rather than soil for growing but the main difference is Hydroponics requires a nutrient solution to feed the plants as well as a pump and timer to regulate feeding and watering.

Aquaponics does not.

The fish provide the nutrients and the fish tank provides the water. Additionally, Hydroponic systems do not have a symbiotic relationship with a living species as does Aquaponics.

Buying an Aquaponics System

In a previous article we learned how to build your own Aquaponics systems, but here we’re going to focus on the different types of systems you can buy. Below you’ll find everything you need to know about buying the right Aquaponics system for use in your home or garden.

Types of Aquaponics Systems

There are three standard types of Aquaponics systems to consider.

A media-based system used gravel beds as the “soil” for the plants to grow. Containers are filled with rocks, gravel, or clay pebbles, and the seedlings are planted directly into this media. The water from the fish tank is pumped upward using a hydroponic system, and passes over the plants, through the rocks or pebbles, and back down into the fish tank.

The utility of using rocks and/or clay pebbles in the Aquaponics system is that they act as a filter. Mountain water is always so crystal clear and clean. That’s because the water has passed through layers of rock formations.

The rocks filter out all the solid waste and other impurities leaving only the clean water. By the time the water filters down into the fish tank, it’s very clean and perfect for the fish to live in.

Not only does the media-based system eliminate the need for waste filtering, but it is actually the better method for growing large plants. Because the rocks are similar to the soil in which the plants would normally grow, plants grow more easily.

You can usually get larger, healthier plants in the media-based systems as they cling to the ‘soil’ in order to grow faster.

There is a wide range of Aquaponics media to include:
  • Peat moss
  • Clay pebbles
  • Gravel
  • Perlite
  • Coir

This is the most commonly available type system, thus one of the most inexpensive to purchase initially.

The downside of the media-based system is that the media tends to be fairly expensive. You have to replace the clay pebbles, gravel, or other growing media in order to prevent the plants from becoming over-saturated with the waste material filtered by the rocks. Eventually, the media will stop filtering the waste as effectively and need replacing.

This media can be quite expensive. The cost of pebble media starts as low as $20 for just 10 liters. If you have a large Aquaponics garden you’ll end up spending easily $100 every time you need to replace the media.

There are two types of media-based systems:

This system has the grow bed separated from the fish tank, and it’s designed to be as simple and user-friendly as possible. It’s the cheaper of the two systems, and it’s ideal if you have a taller fish tank.

The downside is that it’s much more finicky than the other system, as you have to use a timer to ensure the plants are fed and the water doesn’t overflow. Also, there is a much higher exposure to waste and the water level in the tanks tend to fluctuate more–which can be dangerous for the fish.

Continuous Flood/Flow

This system is designed similar to the Aquaponics system above, but there is no need for a timer. The water is always flowing so the plants are continually being fed.

The downside of this system is that the water pump is located inside the fish tank. You’ll find that the plant roots also have a higher risk of being waterlogged, which can cause them to die. Blockages are much more common with this type of system which can also lead to stagnant water.​

The NFT system is designed more for large-scale (no pun intended) production, as it requires an extensive system of PVC piping and filters to keep the water clean and the fish happy. With this system, plants are grown in netted pots suspended by the pipe that feeds them water. A thin trickle of nutrient-rich water is run along the bottom of the PVC pipes, and the plants’ roots are able to reach the water and absorb as much as they need.

If you are growing leafy greens, you’ll find that this is one of the best systems to use. Leafy green veggies have a very small root system, so the roots won’t obstruct the flow of water through the pipes. For plants with larger root systems, however, the NFT system may not be the ideal method.

Another downside to the NFT system is the fact that you need to install a filtration system. Because the water doesn’t pass through rocks or soil, it must be filtered before it drains back into the fish tank. This ups the cost of the system, making it a much pricier choice.

The water is also exposed to the open air, so any chill or heat in the air can lead to water temperature fluctuations. Roots that die and detach from the plant can block water flow in the pipe.

Deep Water Culture

This Aquaponics system is very similar to the floating islands used by the Aztecs of Mexico to grow their plants. Basically, a raft is made (of foam) and floated on the water. Holes are cut into the foam, and the plant pots are inserted into the holes. The roots of the plants dangle in the water after it has been filtered to remove any waste materials.

It’s one of the most commonly used commercial systems and requires high volumes of water to work efficiently. It’s very temperature-resistant and doesn’t experience many pH fluctuations, but it will require an additional filtration system. It’s almost impossible to grow heavy plants (tomatoes and cucumbers among them), but it’s great for leafy greens and other plants that are lightweight and require a lot of surface area.

Now that you know the three types of Aquaponics systems it should be a little clearer to you which system best suits your needs. For a lot more great gardening tips, see our guide on 31 Ways to Make You an Organic Gardening Guru.