Grow

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Food Forever™ Farms

Food Independent

Aquaponics has been evolving since the 70’s in Universities around the US; but the Agricultural Experiment Station, above, at the University of the Virgin Islands (UVI), St. Croix, under the direction of Dr. James Rakocy, has earned world-wide recognition for over 25 years of work in refining aquaponic systems and deserves credit for developing the first commercially viable Raft Aquaponics System like the one pictured above.

Among Aquaponics enthusiasts, Rakocy’s words are often quoted and he is highly respected.

But Raft Technology is not the only way to grow vegetables in an aquaponics system. Another very popular method uses Media Filled Grow Beds with Flood and Drain Syphons.

We will describe these methods below as our Aquaponics World Food Forever™ Farms use a combination to grow prolific amounts of vegetables so fast we call it “Speed Farming”. 

A Food “Life Raft”

Scroll up and down the page here and see the white polystyrene Rafts move.

This is a 4’ x 8’ trough with four 2’ x 4’ polystyrene Rafts in it.

In Aquaponics Technology, just like most technologies, one method does not fit all plants. To grow prolific amounts of flowering plants like tomatoes, peppers, cucumbers, melons, eggplant, corn and many other flowering plants an Aquaponics system takes on an entirely different look and components.

Introducing the Deep Media Grow Bed

The same size Grow Bed with Tomatoes & Melons

Another Grow Bed full of Tomatoes and Melons

Here come the Tomatoes

Beautiful large Cucumbers

Three different kinds of Peppers

Our first grow out of Corn, an important crop

A cluster of Melons

A Raft pumping out different kinds of lettuce

A cooler full of our Butter and Red Oak Lettuce

Farm-sized

Gardens of Hope

A Network Of

These are undoubtedly beautiful specimens of healthy, hardy and huge Leafy Greens, growing in Deep Media Grow Beds with Hydroton. But as you can see in the photo below, there is one big problem that makes this method of growing Leafy Greens problematic, especially if you’re growing area is farm-sized or if you’re growing in a large greenhouse commercially.

The roots of the Leafy Greens get all tangled up in the Hydrocorn; and because Hydrocorn is not inexpensive, the goal becomes one of saving every pebble of it while preserving the roots of the Leafy Greens, especially if you want to deliver your greens with their roots still intact. Separating the Hydrocorn from the Leafy Greens becomes a time-consuming, laborious job that is totally avoided when you grow them in a Raft system.


To your left you see tall stalks of Corn that we are growing for the first time in our Greenhouse Lab. We are so pleased to be able to grow Corn in our Aquaponics Food Forever™

systems because Corn is a staple crop. Go to our Staple Food page to read more about the importance of Corn and other staples that can be grown aquaponically.


You now have the basics of two of the most commonly used types of Grow Beds in an Aquaponics System. The third type of bed has been borrowed from Hydroponics and is called a Nutrient Film Technique  (NFT).

A 3 year old Pepper Plant that’s still going strong.

Here come the Tomatoes!

Here come the Tomatoes. Can’t wait to bite into one of these.

Here’s a Melon from the same plant laying in the Grow Bed

This beauty weights about 3 lbs. and is hanging from the vine.

A close-up of our Corn Stalks!

A tangle of Red Romaine roots and Hydroton.

Huge heads of Red Romaine Lettuce

Huge leaves of Chinese Cabbage

Spinach galore!

When we say our Food Forever™ Farms quite literally become food “Life Rafts" for the food resource challenged community which they serve, this is what we’re talking about.

When a charity, church, NGO, Government, National or International organization places a Food Forever™ Farm in a distressed community, they will be installing food “Life Rafts”.

The pictures to your right demonstrate this highly productive way to grow leafy green vegetables. Rafts work great for leafy greens like lettuce, herbs, bok choy, chinese cabbage and many more Leafy Greens because the roots of leafy greens love being soaked in water 24/7 where they get all the nutrients and oxygen they need as long as the system is well aerated and there is good flow. Leafy greens require a lower amount of nutrients in the water than do flowering plants.

But Raft Systems don’t have to be made out of polystyrene alone. The main requirement of a raft is that it floats. On the right and below are pictures of a raft made out of bamboo. In tropical environments where bamboo is plentiful like Fiji or Bali, a natural bamboo raft would be ideal.



The NFT Method:


In this method of hydroponics, a thin film of nutrient solution is constantly flowing across the plant roots in a tray or trough. This system utilizes very little to zero growing media for plant roots to colonize, which, in the event of pump failure, gives very little time before roots dry out and can lead to loss of crop. The advantage of a NFT system is the high level of oxygen in the root zone and the relative simplicity of the components which consist of watertight gullies, also known as channels. This system is most popular for growing leafy greens and herbs at the commercial production level; and is being adopted for use in Aquaponics systems because the channels can be layered or positioned vertically to save space.

Lettuce Growing on a Bamboo Raft

Bottom side of a  Bamboo Raft

The Raft Method: We call them food “Life Rafts”.

An aquaponics Raft system is made up of two parts, the deep water culture (DWC) trough or bed and a sheet of construction grade polystyrene that is between 1 and 2 inches thick. In aquaponics raft language the word “deep” refers to water that has a depth of  about 6 inches or more.

The nutrient rich water is pumped through the DWC trough, which can be anywhere from two to 100 feet in length. If your trough is sitting on the ground, like the ones at UVI, then you need to add a sump tank to catch the water from the troughs so it can be pumped back up to the fish tank.

The polystyrene rafts are aptly named because they float on top of the continuously circulating water. In large commercial aquaponic raft systems, entire uncut 4 x 8 foot sheets are often used. The rafts are harvested at one end and planted at the opposite end and pushed down the trough in a kind of conveyor belt fashion. When you scroll down the page where our sample unplanted raft sits, the polystyrene appears to move giving you a sense of this conveyance growing technique. In smaller systems, an easy to handle raft is one that is 2 x 4 ft. like the ones shown above.

Circular holes with 2 or 3 inch diameters are cut in the polystyrene where net pots or other devices designed for holding sprouted seedlings are placed. A good standard spacing for the holes is  inches (20 cm) center to center; but some plants require less spacing and others require more.

Notice that the unplanted Grow Bed in the top photo on the left does not have a visible Water Delivery device on it. We have designed our Water Delivery rings so they are deep in the Grow Bed. We call them Deep Delivery Water Rings. This feature keeps the fish waste from accumulating on the top of the Grow Bed.

By delivering the fish waste below the surface of the bed, where it can break down naturally, this process leaves the top of the grow bed clean and maximizes its growing area.

These rules about what kind of plant to grow in what kind of Grow Bed are not hard and fast. Actually, they are quite flexible; and it’s possible to grow Leafy Greens in Deep Media Grow Beds as well as it’s possible to grow flowering plants in Rafts. However, it seems that a consensus is beginning to form and that consensus is that it’s easier and more successful to use both DWC Raft Grow Beds for Leafy Greens and to use Deep Media Beds for flowering plants.

Below are some photos of Leafy Greens that were grown in our Deep Media Grow Beds in the Greenhouse.

The Deep Media Grow Bed Method:

At your left is a Deep Media Grow Bed. It’s located in our Proof of Concept Greenhouse; and Oliver is showing a Tour Group how this Grow Bed works to grow out incredible amounts of vegetables in the fastest amount of time imaginable.

This square Grow Bed offers one meter2 (11 ft2) of growing area, which doesn’t seem like a lot; but just look below at how much one Deep Media Grow Bed of this size can hold. As the photo caption says, this Grow Bed is growing out Tomatoes and Melons.

The rule of thumb for Deep Media Grow Bed depth is 30 cm (12 in) deep; but a range between 18 and 30 cm (7 to 12 inches) is often used. The advantages of 30 cm Deep-Media Grow Beds are many. There is more media in them to cultivate a greater amount of the friendly bacteria necessary to convert ammonia from the fish waste into nitrates for optimum plant growth and allowing for higher fish stocking density. Due to their depth, these grow beds don’t need to be emptied and cleaned as often because the fish waste naturally breaks down as it migrates over time to the bottom of these deep Beds. This feature makes Deep-Media Beds a must.

The word “Media” describes the “Substrate” that is placed inside the Grow Bed to function in many capacities, one of which is to hold the plants that are growing in the Grow Bed. Our trusty Wikipedia definition of “Substrate” has many faces depending on what field is being discussed. In Biology, a “Substrate, is the natural environment in which an organism lives, or the surface or medium on which an organism grows or is attached.”

This is the perfect definition of the Media in a Grow Bed because there is a lot more growing in these Grow Beds than the plants, which brings us to the other very important function of the Media in a Deep Media Bed. The Media provide a place for the beneficial bacteria to attach themselves. And now we just entered the domain of biology.

In that top picture on the left, you see red pebble like spheres. This is expanded clay. It is manufactured using the best qualities of pure clay. They are fired or “popped” in an open rotating furnace using high grade clean fuels. This guarantees the absence of heavy metals or other contaminates.

Now back to biology. Just like the Fish Tank, the Grow Bed is an ecosystem unto itself. With the bacteria attached to the bed’s media, it functions as a Bio-filter breaking down the fish waste as it passes through the Bed. Bio-filters work by growing friendly bacteria on a substrate, like gravel; and here is where expanded clay has the advantage. Unlike gravel, expanded clay is porous and, therefore, rich with lots of surface area where these friendly bacteria live and consume the passing fish waste breaking it down into soluble nutrients that become available for use by the plants.

When the water is run through the Grow Bed, these transformed nutrients get taken up by the plants and the cleaned water is then returned to the fish ready for the next cycle. The scientific name for this process is called “Nitrification”. From this process, Nitrates are created, which is what you want to end up with--a high Nitrate count while your Nitrite and Ammonia counts remain very low because they can bring toxicity (even death) to both your plants and especially your fish. So, one of the most important jobs of a Deep Media Grow Bed is to act as Bio-filter. In an aquaponics system, this is a necessary process as it could not properly function without a working Bio-Filter.

When using DWC Grow Troughs, there is only water. The Bio-Filter is then created in a separate, stand alone component that is not part of the DWC Grow Bed.

So, the Deep Media Grow Bed grows natural, friendly bacteria as well as plants. Flowering plants require high Nitrate counts in order to put out their fruits and vegetables. Tomatoes, especially, require lots of Nitrates once the tomatoes start appearing on the vines. Tomatoes also require pruning as they grow lots of branches whose sole purpose is photosynthesis, which is the process that turns sunlight into chemical energy and stores it in the bonds of sugar. Once the tomatoes start to appear, these extra branches are no longer necessary and need to be trimmed off so all the nitrates can go into the fruit rather than the leaves. Many of us think of tomatoes as a vegetable; but they are actually a fruit.

In the middle of the unplanted Grow Bed in the top photo on the left you see a round black tube protruding out of the bed. That is the Bell Syphon. The Bell Syphon is what allows the grow bed to drain its water out when filled, creating the flood and drain action cycle.

Flowering plants need more oxygen on their roots than do Leafy Greens so a controlled flood and drain cycle allows for a selected period of time when there is no water in the Grow Bed; and the plant roots have an opportunity to take in lots of oxygen.

We have designed our grow beds to move the water in and out quickly. We call them Rapid Cycle Grow Beds. We also control the overall timing of each grow bed’s cycle.

Beautiful Bak Choi roots