Aquaponics Grow Bed Design For Thriving Vegetables

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Aquaponics Grow Bed (Updated 2019)

Aquaponics Grow Bed RaftAn  aquaponics grow bed  is one of the 3 main components in any aquaponics system, the other two being the fish tank and the water transfer system. The grow bed is often an aquaponics biofilter itself in that, the natural bacteria takes up residence on the surfaces of the gravel media. This makes it a self contained ecosystem of bacteria processing ammonia from the fish, and converting it to nitrates that become nutrients for the plants.  As a grower, you will find that this is one of the most important benefits of Aquaponics.

 

Aquaponics Systems can be used for commercial purposes that require large spaces covering up to several acres of land. However, this website focuses primarily on household needs for gardeners that build their systems in the backyard, in greenhouses, the garage, and other indoor areas. There are 3 basic kinds of aquaponics systems,  the Grow Media-filled Bed, the Deep Water Culture or Raft System, the Nutrient  Film Technique (NFT) System, and the , Chop Systems together with Alternating Flood and Drain (AFD).  The first 3 types are modified versions of Hydroponics Systems and the last 2 were developed as backyard Aquaponics systems. Many growers have also modified the hydroponic Grow Towers (Vertical) and Ebb and Flow (Flood and Drain) systems into aquaponic system hybrids. We’ll go over all 6 of these in our Types of Aquaponics Systems section below. 

Keep in mind as you research aquaponics online that the terminology, as well as system types, vary quite a bit. For example deep flow culture (DFC) is virtually the same thing as Deep Water Culture, and Alternating Flood and Drain is mistaken for Ebb and Flow (flood and Drain)…. So don’t be confused by the names.There are virtually millions of gardeners getting on board with the benefits of Aquaponics and Hydroponics systems, and many are experimenting with design modifications so the terminology begins to modify with it. The basic systems you find here are to help you decide which ones work best for you.

Grow Bed Containers

 

Grow beds are a container that provides an area for the plants to grow in. In this grow bed environment, all types of seedlings can thrive optimally including vegetables, tropical house plants, orchids, flowers, shrubs and even tree start ups.

There are literally dozens of variations in aquaponics grow bed layouts. Most growers will start with a simple design that could be used for a small backyard aquaponic system. The bigger they are, the more complex they can get. They may or may not need accessories like bell siphons,  water pumps, and bio-filters etc. You’ll have to decide according to the type and volume of crops you want to grow. In this article we’ll go over  the more popular category types of Aquaponics Systems that are in use today.

Each aquaponics system we’ll go over below is a summary of their function and benefits to give an overall idea of its structure. Each one will also have a link to our page that gives you full details  of these systems so you can decide on which one works best for your needs. BTW, these systems are also used in Hydroponic systems, the main difference being the absence of fish. 

 

 

Aquaponics Materials List

 

Aquaponics Grow Bed diagramMaterials to build an Aquaponics grow bed are usually made of plastic, fiberglass, or wood. These containers are then covered with polyethylene sheeting or watertight rubber on the inside walls and bottom.

Be sure you’re are using inert materials to build your  grow bed with. This means resources that are chemically inactive and do not contain toxin’s that can bleed into the water. For example, treated lumber and many metal alloys like iron can corrode and contaminate the system. Always be attentive to the sanitation factor in your aquaponics environment. A balanced microcosm ecosystem is needed for the  safety of the fish, the plants, and beneficial bacteria. Unwanted toxins can also disrupt the pH levels required. More about the  pH levels recommendations .

Aquaponics Media Options

Aquaponics Grow Media OptionsA popular aquaponics grow media to fill the insides of an Aquaponics Grow Bed, is Lightweight Expanded Clay Aggregate (LECA). You can see in this image how it becomes a support for the plants while providing oxygen and creating lots of surface area for the bacteria to collect. These marble sized pebbles are also known as Hydroton, lightweight clay pebbles that are hydroponic substrates and available online and local nursery’s . Lava rock and porous gravel can be used as an alternative, just be sure to stay clear of any that contain marble or limestone as these can affect the pH levels. In smaller layouts, particularly Hydroponic Systems, perlite, vermiculite, and other such media are occasionally used.

 

Each aquaponics system below is a summary of their function and benefits to give an overall idea of its structure. Each one will also have a link to our page that gives you full details  of these systems so you can decide on which one works best for your needs. BTW, these systems are also used in Hydroponic systems, the main difference being the absence of fish. 

 

Types of Aquaponic Systems

1. Aquaponics Grow Media-filled Containers

Aquaponics Grow MediaAn aquaponic grow bed container may just be the most important component in the system. These containers can take up the greater part of space used when you start adding several of them. They also supply you with all of the produce that you will be harvesting.

It is filled with a media of clay pebbles (usually Hydroton) at a level of 2 inches from the top. The image to the left is a typical 36 X 20 inches grow bed made of plastic, most of which are 12 inches deep for optimum vegetable variety and filtration.

The Grow Bed as a Biofilter

Water flows into the container from the fish tank bringing along with it fish waste. The waste is converted into nutrients by bacteria colonies that populate on the surface of the porous media pebbles. The conversion process cleanses the water like a filter and is circulated back to the fish tank.

For more details on Aquaponics Grow Media Beds go to the Difference Between Hydroponics and Aquaponics part 3

2. Deep Water Culture

deep water culture aquaponicsDWC (deep water culture) is also known as Floating Raft System aquaponics, though usually in large systems in commercial usage. Another hybrid from Hydroponics Systems, the deep water culture aquaponics is light on upkeep and ideal for small root plants like lettuce and other large leaf vegetables. These systems can be designed for small and large garden layouts.

It sometimes utilizes rafts that float on the container holding plants in net cups and this is when it is referred to as a Raft system. The netting in the cups allow the roots to dangle below into the container of nutrient-rich water.

Go to the Difference Between Hydroponics and Aquaponics for more details

3. NFT Aquaponics System (Nutrient Film Technique)

NFT Aquaponics SystemNutrient Film Technique layouts are fairly easy to build and cost less then most other systems. It also doesn’t used a lot of water through the channels. For example, a 60 Ft channel would only use one gallon of water from one end to the other. This keeps heating & cooling costs down.

In this type of System, long PVC or vinyl tubes/channels are used as a grow environment. A sparse film of water is pumped continually through the channels from the fish tank, carrying nutrients to the roots of plants in net cups above. In an Aquaponics system the addition of a fish tank can be a problem though. With so little amount of water in the channels, fish waste can clog up the system drying up the plants in a matter of a few hours. 

Precautions must be taken with the tubing that runs to and from the channels. Additional filtration is needed between the fish tank and the grow channels to filter out the waste solids.
Go to the Difference Between Hydroponics and Aquaponics for more details

4. Aquaponics Chop System and Alternating Flood and Drain

The Chop, or Constant Height One Pump, was invented in Australia utilizing a fish tank, grow bed)s), and a sump tank. As with other aquaponics systems that have builtin biofilters, the grow bed media provides nitrates from the bacteria population. Like the Ebb and flow system, a bell siphon is recommended to keep the water from over flowing so the system can run continually from the pump.

The Alternating Flood and Drain is very similar to the Chop system. In this case though, there are 4 to 8 grow beds with media that provides nitrafication. The grow bed containers are flooded alternately by a pump using timers and indexing valves. It also doesn’t need a sump tank.

Go to the Difference Between Hydroponics and Aquaponics for more details

5. Aquaponics Tower Grow Bed

strawberry towers aquaponics systemsAn aquaponic tower is a vertical structure that works well with small plants like strawberries, lettuce and other small rooted plants. The vertical channels can be made of a vinyl fence post or even 3 inch PVC pipes up to 10 Ft long.  Small pockets are shaped that support small cups inserted with grow plants up and down the length of the tower.

Because of its upward structure, tower systems are ideal in situations where you have a limited area of space. This is ideal for balcony’s, roof tops, and small patios etc.

 The fish tank component will need regular monitoring to ensure that nitrates from fish waste,  as well as temperature and pH levels, remain at the proper limits. As with the Hydroponics version, the towers are supplied with the nutrient-rich water from a pond-type water pump. The water enters the PVC channels at its top and then uses gravity to flow downward providing the plants with the needed solution. More Details About Aquaponics Tower Here

6. Flood and Drain Aquaponics (AKA Ebb and Flow)

 

Flood and Drain AquaponicsThis refers to an Aquaponics Grow bed that is flooded with water from the fish tank, and then drained back to the tank below. This grow bed optimizes the benefits of nutrient-rich water and bacteria that are present. Since this is an ongoing cycle, the pebble media is wetted constantly keeping it aerated with oxygen continuously. The same goes for the bacteria living in the roots of the plants, and the oxidation created when the water is returned to the fish tank.

 Go to the Difference Between Hydroponics and Aquaponics for more details

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