Energy-Saving Devices for Aquaponics in Cold Climates

New Energy-Saving Devices for Aquaponics in Cold Climates
– by Colle and Phyllis Davis

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We receive many inquiries from people who live in very COLD climates who ask us, “Does aquaponics work in cold climates?”

And our answer is always, “YES IT DOES! In fact, it’s actually easier to heat a greenhouse than it is to cool a greenhouse!”

The energy cost of some aquaponics systems is so low it is almost a non issue. Many people chose to incorporate solar or other alternative power to operate their systems with great success. There are some new(er) technologies that may be helpful in planning an aquaponics installation or even retrofitting an existing installation.

greenhouse lean toThe first suggestion is the use of the outer wall of an occupied house as part of the (greenhouse) structure. Using the wall of a house as the north wall of the greenhouse makes perfect sense to protect the interior of a greenhouse structure from cold winds, and even if there is some electricity used to run the aquaponics system, on an annual basis, the greenhouse will have a CARBON NEGATIVE impact. Now really, how cool is that?

The insulated wall of a house means that the wall is never cold and much less heat is needed to keep the greenhouse above freezing. The second effect is having a door into the greenhouse in that wall so the greenhouse is entered from the house instead of entering the greenhouse directly from the outside. Two benefits here: The warm air from the house can enter the greenhouse and the cooler air can be warmed by the house’s heating system. But, “WAIT,” you say, “. . .  that will cost money to heat.” Yes and when the sun comes out, heat moves back into the house and the runs the other way; heat from the greenhouse comes pouring into the house. Think GIANT solar heater.

sunsunglassesOn clear sunny days, even in very cold weather, the heat gain in a greenhouse is very impressive. Even with outside temperatures ten degrees below freezing, the interior of a building-mounted greenhouse can very quickly raise into the comfortable-to-warm range. Now the greenhouse is reducing the heat load on the house itself and is now actually contributing to lowering the heating costs. The small amount of heat needed to keep the greenhouse above 50° F (4° C) is very quickly paid back on sunny days no matter what the temperature outside happens to reach. (Greenhouse needs to be a minimum of 65 degrees F with additional grow lights to extend the length of the day during winter months to grow blooming vegetables like tomatoes, peppers, cucumbers.)

Insulation can be used on the non heat/light gathering areas. The entire north side of the greenhouse can be insulated with 4 to 8” of insulation. Painting the interior of the insulated side a bright white reaps the advantages of the insulation and the bright white bouncing the light around. The east and west walls can be insulated up to the 3 or 4’ level with no loss of effectiveness in the sun capture.

A stem wall is the wall surrounding a greenhouse (image below)

portable-farms-gravel-mediumStem walls around the side of the greenhouse structure can be insulated or in warmer climates, can simply be concrete block to raise the overall height of the greenhouse to enclose more volume of air making the system more effective and easier to control.

Roof vents instead of exhaust fans are also effective. Roof vents are the modern trend in greenhouse design and with these vents and their air intake vents screened, the insect problems are vastly reduced to almost nil. The reductions in energy costs are amazing. The small motors that control the vent mechanisms require a very small amount of electricity and are only ‘on’ for a few minutes each day.

Solar heating for the fish tanks can also be done relatively inexpensively and with few, if any, electrical requirements, these systems quickly pay for themselves.

Solar panels to provide the electrical needs of the installation have come down dramatically in price over the last decade and with the reduced needs of the installation, the cost of going solar has become both viable and a cost savings.

Monitoring systems are still a bit expensive, but the need to monitor any aspect of the installation may be reduced to the point of only needing catastrophic failure notification.

There are other small tweaks that can be incorporated into any aquaponics greenhouse to reduce the energy requirements and each time these requirements are lowered, the ROI becomes better and better. Let the imagination run wild or contact PFAS LLC for more information on improving that current or dream aquaponics greenhouse.

Think Ahead for Winter Growing

Winter Growing in Aquaponics
– by Colle and Phyllis Davis

Yes, you can grow a variety of crops YEAR ROUND in aquaponics in acclimatized greenhouses if you install grow lights for use during winter months to extend the light of the day. In order to grow food you need six hours of direct sunlight per day or ten hours of grow lights. 

However, there is a caveat, the ambient air temperature still determines which crops are easier to grow in cold weather or hot weather. For example, It’s easier to grow fragile greens in cooler weather. Let’s use bib lettuce, buttercrunch lettuce or red leaf lettuce as an example. If the air temperature is too hot, those lettuces will not grow to their maximum size, in fact, they may BOLT before they have even reached their average  growth and are best grown in cooler temperatures. However, in hot seasons, there are far more heat-resistant lettuces available such as Romaine (cos).

Komatsuna summerfest - An Asian Green we prefer over bib lettuce.

Komatsuna summerfest – An Asian Green we prefer over bib lettuce.

Despite the fact that Portable Farms® Aquaponics Systems are ‘housed’ in acclimatized greenhouses and provide the ideal water temperature for growing lettuces at 78 degrees F, all seedlings and growing plants (of all varieties) still react to climatic conditions:

  • Air temperature
  • How air temperature effects the temperature of the gravel in the grow beds
  • Humidity levels
  • Sunlight exposure levels
  • Day length
  • Root drainage and water flow
  • Appropriate pH balance and appropriate nutrient levels.
Phyllis Davis harvesting greens for a luncheon. That's was one heck-of-a-salad. Yum.

Phyllis Davis harvesting greens for a luncheon. That’s was one heck-of-a-salad. Yum.

In order to create maximum crop yields, careful consideration is always paramount for seed variety and selection for growing at optimal levels by experimenting with small seed batches until you find a seed that offers maximum production in your farm.

Before deciding on one particular seed or seed variety for your farm, experiment first. Since every area of the world offers a variety of seed choices in that country or region, take your time to speak with local growers and seed suppliers to see which seed will work best for you, in your climate, and then purchase a few different varieties of small packets of seeds to experiment in your aquaponics system until you find the seeds that work best for you and your family or future customers.

All varieties of lettuces grow to harvest between 40 and 75 days and most lettuce seeds available for sale have been developed for growing hearty, healthy heads of lettuce in both cool weather and hot weather conditions. 

Phyllis Davis, Co-Inventor, holding ONE HEAD of India Mustard. Wow! That will make one gigantic salad!

Phyllis Davis, Co-Inventor, holding ONE HEAD of India Mustard. Wow!
That will make one gigantic salad!


Cool weather lettuces we recommend

  • Head and Big Lettuces: Arctic King, Buttercrunch, Matchless, North Pole, and Burpee’s Bibb, Red Sails, Prizehead
  • Romaine: Parris Island Cos (the most common)


Heat-tolerant lettuces we recommend:

  • Head lettuces: Gulfstream, Vista, Oak Leaf, Great Lakes, Ithaca, Gator (highly recommended by University of West Virginia). Burpee, Igloo.
  • Leaf Lettuces: Simpson Elite, Burpee™s Heatwave Blend, Black Seeded Simpson
  • Romaine Lettuces (cos): Snappy, Terrapin, Pomulus.
  • Red Lettuces: Redfire and Red Sails.

Growing Food in Grocery Bags

Growing Food in Grocery Bags
– Colle and Phyllis Davis

Free tutorial to grow food to feed your family. Affordable and Fun!



If you’ve been following our theme this summer, we’ve been offering alternatives to aquaponics to grow food to feed your family with  AFFORDABLE AND SIMPLE methods. CLICK HERE TO SEE  THE FREE TUTORIAL FOR GROWING FOOD IN A GROW TUB.  (A few images of these grow tubs at bottom of this article).

You will love this easy method for growing food in grocery bags. You can put these bags on a small table on your patio or porch and reuse the bag when the plants are harvested.

How To Grow Salad In Plastic Bags | DIY Joy Projects and Crafts Ideas

  • Seeds:  We recommend you try growing lettuce, cabbage, Swiss Chard, kale, basil, radishes, turnips and even potatoes. If you grow a plant that is top heavy like tomatoes, cucumbers, or beans.  Note: Blooming plants (as I just listed) require far more care including trellis care and far more water than growing basic greens.
  • Grocery sacks (the thin plastic bags used in many stores to bag groceries).  A second grocery sack to wrap around bottom of the first bag with soil or a cheap (hotel style) shower cap you can get a dollar-type-stores.
  • Table must have slats (space between boards) for the water to drain out of the bag. The table shown in the picture is 3’x4′ and will hold about 20 grocery sacks. 
  • Potting soil or slightly sandy garden soil.
  • 6-hours of direct sunlight per day. In the spring, fall and winter, you can extend the day length from 4pm to 7pm with the use of LED (red/blue spectrum) grow lights. Or you can grow in your garage by using a grow light 18 hours per day. Example, here’s a $20 grow-light strip from Walmart.
  • Shade cloth in extreme sun exposures. Last week, the farms (pictures below) on this page needed shade to protect the young plants and seedlings from 100-degree F. we are currently experiencing here in Central Virginia. On the first day of the heatwave, Colle and I got up before sunrise and searched the basement for a box of gauze drapes we had stored there. We used the drapes as a temporary sunshade to protect our gardens during this intense heatwave. The plants responded immediately and perked up.
    • During our mild Virginia winter months, we are going to wrap our new ‘grocery bag structure’ in clear plastic to protect it from the cold.  We will also use a space heater on the ground (on a timer for intermittent power) underneath the table if the temperatures drop.
  • We also sprinkled our world-famous FF Mineral Rock Dust on the seedlings and the plants to provide them with ample amounts of calcium, magnesium, potassium, and iron.

The grow table in the foreground was built 40-days ago and the plants are already near harvest as you can see from the image below.

(Pictures below) Grow Table Tubs for Above Ground  German Growing Method, Hugelkultur. 75% of these tubs are filled with dried trees and mulch as a nutrient source for the plants.


The cost of this garden was approximately $100 for the materials. You can prepare the parts and then assemble it anywhere that receives six hours of direct sunlight. Some vegetables require less sunlight, but most like lots of sunshine.

40 day after planting. Basil. Tomatoes. Radishes. Carrots.

Teach Your Daughter Aquaponics

– by Colle and Phyllis Davis

Besides all the love and attention you currently lavish on her, what else can you teach this joyful addition to your life  – – this legacy to your genes, to insure her health and survival? Can you do anything differently than your parents did for you to give her a better-than-average chance to pass on your genetic material to future generations?

Yes, the biggest advantage you can give your child today is an aquaponics education so she will always have the knowledge, skills and abilities to grow her own nutritious, healthy food. Even if she is only three years old, buy her a Portable Farms Aquaponics Systems and teach her how to operate it.

As much as we all hate the thought, the worlds ability to feed and provide water for all seven billion of us on this spinning planet is becoming a cautionary tale. Today, there are over 1 billion people without access to clean drinking water. Frightening thought! Young girls, especially teenagers are fascinated with the Portable Farms Aquaponics Systems.

Of the thousands of people who have toured our installations over the years, the young teenage girls are the ones who have asked the most questions, and often the best questions, went back into the greenhouses the most often, and were the ones pressuring their parents and grandparents to buy one so they could, ‘have some of these wonderful vegetables and fish in our backyard’ even before they left the property. These young women are the vanguard of the future; let them be working for you and your family.Teaching skills to a child is what parents and grandparents do, it’s their job.

Teaching the next generation to be better prepared and more productive, live healthier and longer lives and to prepare their children to continue the process is how we have arrived here. Our parents did their best in their efforts to raise us to become responsible adults. They may have made some silly or sad mistakes is the process, but for the most part they were there to teach us to survive and sometimes even thrive.Now you can add a new layer of protection for your daughter(s) or granddaughter(s) by teaching her/them how to raise their own fresh organic food, even in an urban environment. Oh, the young sons are not being left out of this equation; they simply are much less interested in raising food until they have daughters of their own. In one of the most interesting anomalies of life, men, at some level, understand that their daughters have a much better chance of maintaining their linage than their sons. If you are a man and have a daughter or granddaughter, you have a very deep understanding of this article.

Keep pH BELOW 7.2 in Aquaponics

Nutrient Absorption Occurs BELOW 7.2 pH
– by Colle and Phyllis Davis

Testeur Ph d'une piscine individuelleIf the pH gets too near or above 7.2 in your Portable Farms® Aquaponics System’s Fish Tank, your plants cannot absorb the nutrients in the system and creates a NUTRIENT SHUTDOWN and your plants will begin to wither, show systems of leaf curl, begin to yellow, have stunted growth and not produce growth or blossoms. In effect, the plants are starving to death.

The Portable Farms® Aquaponics Systems are designed to accomplish this adjustment in an extremely easy manner. Checking the pH in your system at least a couple of times per week is vital, especially as the vegetables approach harvest time; this is an inexpensive process to increase production in the grow trays. This simple checking and adjustment will result in more bountiful harvests of healthy and nutritious produce.

Each plant has a preferred range of pH, or parts Hydrogen, that creates an ideal growing environment for the plant.

In aquaponics, this adjustment is very easily when the water flows through the system. To ‘increase’ the pH means to make the solution more alkaline and to ‘decrease’ the pH means to make the solution more acidic. There are quick and very inexpensive ways to change the pH of water in an aquaponics system.

When adding any agent to adjust the pH levels in your system, allow several hours, and better yet, monitor your system over a day or two before trusting the testing medium results.

Testing can be done with simple swimming pool test strips or with sophisticated scientific instruments that have been designed for the task. Both work very well and if you use both, be prepared to have two very different readings. What you are looking for is consistency using one method. Using both is confusing and makes adjusting the water much harder. (We know from experience . . .)

We check the pH in our fish tanks two or more times per month to make sure the pH is below 7.2.

Each plant has a preferred range of pH, or parts Hydrogen, that creates an ideal growing environment for the plant.

  • Plants in Portable Farms Aquaponics Systems prefer a pH in the 5.8 to 6.8 range, or even a slightly lower range.
  • Fish prefer a little higher pH and to keep both organisms happy, the water in an aquaponics system needs to be adjusted.

The measurement of pH is how acidic (6.9 and below) or alkaline (7.1 or above) a liquid is at any specific moment. This pH measurement is not about the water’s hardness, that is a measurement of the dissolved mineral content in the water, and it is measured in a different way.

In aquaponics, this adjustment is very easily when the water flows through the system. To ‘increase’ the pH means to make the solution more alkaline and to ‘decrease’ the pH means to make the solution more acidic. There are quick and very inexpensive ways to change the pH of water in an aquaponic’s system.

If you are trying to grow vegetables with very different pH requirements in the same grow tray, plant the heavy feeders at the beginning (top) end of the tray and furthest from your fish tank, where the water flows into your grow tray, favoring their pH requirement and the light feeders at the end where the water flows out.

meterWhen adding any agent to adjust the pH levels in your system, allow several hours, and better yet, monitor your system over a day or two before trusting the testing medium results.

Testing can be done with simple swimming pool test strips or with sophisticated scientific instruments that have been designed for the task. Both work very well and if you use both, be prepared to have two very different readings. What you are looking for is consistency using one method. Using both is confusing and makes adjusting the water much harder. (We know from experience . . .)

We use a Microprocessor Conductivity & TDS Meters with Automatic Temperature Compensation with Automatic Calibration to check the water in our systems (image left).

Rent a Greenhouse for a One Year Return-on-Investment

Rent a Greenhouse for a One Year Return-on-Investment

– by Colle and Phyllis Davis

Rent a greenhouse instead of building one for your commercial aquaponics system and get a one year return on your investment.

In Southern California (obviously, a biased sampling) the cost to lease a greenhouse of 25,000 to 75,000 sq ft is from US$1,500 to US$3,000 TOTAL.

GreenhouseLet’s do the math and see how this investment pencil’s out:

A very solid rule of thumb on the cost of a PFAS Module which includes the grow trays, the fish tanks and all of the related lumber, pipe, liner and the PFAS Kit, is US$2,100 per Module. A 10,000 sq ft installation will contain 28 to 32 Modules depending on the specifics of the layout.

Grab a Pencil and Let’s Do the Math

Multiply the cost per Module US$2,100 times the maximum number of Modules 32 and your install cost becomes US$67,000. Then comes the greenhouse. [This cost is normally THE most expensive part of an aquaponics installation.] Let’s use a three year lease and figure the ROI on the yearly maximum rate of US$2,000 for a 10,000 sq ft greenhouse or US$24,000.

You still have labor, electricity, fish, seeds and misc and these total approximately US$80,000 per year. These figures are San Diego, California figures, California labor costs, San Diego Gas and Electric power costs and the local water district water costs (not inexpensive).

First Year Expenses (Averages)

  • Your first year investment will include the cost of building the Modules    
  • The total operating  costs                                                                                            
  • Rental on the greenhouse
  • First year total

The gross income based on a mixed production of both greens and fruiting plants such as tomatoes, peppers, cucumbers and beans is approximately US$185,000 of income per year resulting in a net-net income of approximately US$80,000 per year.  Specialty or custom ordered vegetables dramatically impact this figure on the high side. For example if all basil were grown the income would almost quadruple to over US$600,000. Cucumbers are even better producers, but remember, these specialty crops and are NOT high volume crops.

These figures show a total payback over slightly over two years. US$80,000 x 2 years = US$160,000. Oh, wait, the initial capital investment was less then US$100,000 so the real payback is in a little over ONE YEAR.

Now look at the third year numbers. There are operating costs and rental costs, that’s it. The output has increased approximate 20% as the system ages and cures so using the initial income of US$185,000 and not the US$220,000 (the 20% increase) it will really be producing,  your US$80,000 per year (or US$116,000 with the increase in production) is now pure profit. Almost enough for some people to live on comfortably.

Contact us today for specifics, but first read Commercial Aquaponics and have two items is place, 1) your money or your investors money to cover the project’s cost, 2) a location to build your PFAS Modules so you can be in business in less than six months.  Remember, we even train your operators, guarantee our systems and are here to help.

Aquaponics Food Tastes Great! GROW YOUR OWN

Aquaponics Food Tastes Great! GROW YOUR OWN
– by Colle and Phyllis Davis


Eight Green Bean plants grown in a Portable Farm yielding
200 green beans six weeks after planting.

Isn’t it time to simplify your life and enjoy quality time and food?

Globally, self-sufficiency is becoming main stream in 2020 as individuals and communities unite to find ways to source affordable housing, create food and water safety, find access to quality health care, organize opportunities for living wages and find support for children and our aging population. These topics are as realistic today as there were 200 years ago when the world population was only a little over one billion people in 1814, compared to today’s 7.5 billion world population.

Today, natural resources are dwindling and the need for shared responsibility for self-sufficiency is a growing trend for assuring peace and prosperity in families, communities and the world.

Aquaponics is affordable and it’s ONE VIABLE SOLUTION to the issues related to food safety and added self-sufficiency because:

  • People of any age can participate – adults, children, seniors and those with disabilities
  • Aquaponics systems can be located in urban communities near the population of cities. It has been proven that urban neighborhoods with community gardens have a sharp decrease in crime because of neighborhood pride.
  • Aquaponics systems are as effective in outdoor greenhouse structures as they are in abandoned warehouses or parking lot basements.
  • Caring for food is a nurturing act that has therapeutic benefits that are good for the soul.

Broccoli grows well in Portable Farms! Large, tender, delicious and the plant offers several rounds of new blossoms after initial harvest. Broccoli grows well in Portable Farms! Large, tender, delicious and the plant offers several rounds of new blossoms after initial harvest.

Aquaponics is a simple growing system that provides an all-chemical free environment that delivers all the nutrients and water that plants need to grow to perfection. In addition, the structure (generally a greenhouse) protects the plants and fish from climate changes (rain, cold and heat), wind and predators (bugs, birds and bunnies).

If you add up all the benefits to the plants and fish, it’s paradise on earth from them as a growing environment because there is no ‘stress’ on the plants or the fish to protect themselves from predators or to source food or freshly oxygenated water. Plus, the daily maintenance for aquaponics is minimal and redundant: 1) plant and harvest plants, 2) feed the fish. REPEAT the next day. There is no watering, no weeding, no chemicals, no fuss, no muss.

  • All of the food (nutrients) for the plants arrives before the plants need it, or want it.

  • The water is always available and it is refreshed a couple of times a day

  • The light levels are always perfect in the structure

  • The air circulates in a gentle fashion to help with pollination and to help avoid dampness in the structure

    • The temperature is pleasant and varies a bit so as not to be monotonous

    • There are no bugs or weeds or poisons or harsh chemicals used to contend with, ever. 

    • The water in the Portable Farms Aquaponics Systems turns over ENTIRELY twice a day. Plus, all of the heavy fish poop has been removed and rerouted so it never flows into the Grow Tray or has contact with the plants.

Phyllis Davis harvesting Tokyo Bakana, an Asian Herb we use as a great lettuce for salads. Delicious and easy to grow in aquaponics.

Phyllis Davis harvesting Tokyo Bakana, an Asian Herb we use as a great lettuce for salads. Delicious and easy to grow in aquaponics.

As a result of an ideal environment:

  • The plants grow faster than the seed packets say they will

  • Food grown in an aquaponics system is much healthier than ‘regularly’ grown plants, and as a result, they are healthier for you, they TASTE BETTER and are higher in nutrition.

  • The food in an aquaponics system is grown without any chemicals (think about it; if chemicals were used, it would kill the fish). The growing food is more beautiful with each passing day

  • The plants mature in less time and require 90 to 95% less water than their dirt-grown friends

  • The plants stay clean and dry at all times

  • They are harvested when they are at their peak of ripeness and maturation which means their flavor and nutritional content are always at optimal levels

  • They are simply the best vegetables on the planet.


Here is The Difference Between Hydroponics and Aquaponics

Here is The Difference Between Hydroponics and Aquaponics
– by Colle and Phyllis Davis

  • A commercial aquaponics system creates immediate jobs and food for semi-skilled people trained in less than a week.
  • Permanent full-time jobs and year round food production in three months in greenhouses or warehouse.
  • Grows pesticide free food, table vegetables and fish, raised in simple yet revolutionary new technology that replicates nature.
  • Installation can be solar powered.Total sustainability can be achieved by selling most of the food production to local markets.

Hydroponics (image above of lettuces) is a very recent technology first noted in the 17th Century; the name itself was only coined in 1937 from the Greek words for ‘water’ and for ‘work’ by William Frederick Gericke of the University of California at Berkeley. He grew a 25′ tomato plants in his backyard using only mineral salts in water.

As amazing and productive as hydroponic is, there is a built in problem with the technology. The nutrient solution used in the growing of the plants eventually has to be ‘changed out’ or it will become toxic to the plants, even if the system is being run organically because some of the nutrients become concentrated in the water and even adding water to dilute it, there comes a time when it must be changed out. Therein lies the rub . . .

Hydroponics lettuce root.

The ‘liquor’ as it is called, is now designated by the EPA as toxic waste and must be disposed of properly by qualified personal using approved techniques. Another way to say this is that the waste disposal for hydroponics is expensive and needs to be disposed of by experts. This makes the hydroponic waste removal a much larger expense than most people realize and it’s a topic that’s almost never discussed by those selling hydroponic systems.

Hydroponics has a much older and more benign sister, aquaponics that has been around for over 4,500 years and is the exact same system that nature uses to break down waste to reuse the resulting byproducts to grow new plants and this process has been going on naturally for billions of years.

In aquaponics, there are no toxic chemicals used in the system. After all, chemicals would kill the fish.

Oreochromis Mossambicus Tilapia

The waste products in aquaponics are non toxic, usable on other plants and can even be dumped down a sewer system because they will not harm sewage systems. The waste from an aquaponics system is a valuable fertilizer for plants, shrubbery, trees, or grass. One owner of a small commercial Portable Farms® Aquaponics System even sells his Settling Tank waste as an organic fertilizer and gets US$25 per 5 gallon container and the client picks it up at his greenhouse. Considering that each Module of Portable Farms® produces approximately 50 gallons of waste water every six weeks which can become a nice extra source of income for the installation owner. 

Insecticides that help control pests on the plants will nearly always kill the fish. Pesticide free-food creates a safer and healthier food supply. Portable Farms® Aquaponics Systems use NO dirt and no chemicals (insecticides or fertilizers) to grow the plants.

One Grow Table of blooming plants in a Portable
Farms Aquaponics System: tomatoes, cucumbers and beans.

Today, your family can enjoy one of the oldest food-growing technologies wrapped up in a modern, easy to build and operate system in your own backyard, patio or greenhouse.

  • There have been over 300 different varieties of plants  that have been tested and can be grown successfully in a Portable Farms® Aquaponics Systems. For example, lettuce is considered a variety but there are hundreds of variations of lettuces that grow well in aqupaonics. The same is true for peppers, beans, etc.
  • The major food groups that are not recommended for Portable Farms® are root vegetables (carrots, potatoes, onions, etc.) and field crops such as corn, wheat, soy or rice. Perennial plants (strawberries, blackberries, asparagus, etc.) are not recommended because the plants are dormant many months each year and do not produce harvestable food year round. Plus, we recommend growing all plants from seeds and not bringing in plants raised in soil into the structure which can introduce pathogens that can harm the other plants in the structure.

Basil is a High-Value Crop for Aquaponics

Phyllis Davis harvesting fresh delicious basil
from Portable Farms Aquaponics System

Basil – A High-Value Crop for Aquaponics
by Colle and Phyllis Davis

Basil is a high-value crop for aquaponics. It is enjoyed as a fresh-leaf herb on meats and vegetables, prepared in sauces such as pesto, or dried and used in many recipes in cultures throughout the world. Basil grows well in aquaponics systems because of the ideal growing conditions created with warm water and ample sunlight.

When basil is grown in traditional in-ground growing, it is a ‘summer crop,’ but when grown year round in aquaponics systems, it is considered a ‘high value crop,’ especially when sold locally in cold climates when basil would normally be normally be considered ‘out of season.’

Basil growing in a  Portable Farms® Aquaponics System. These plants are 24″ tall and were grown in 55 days. Pesto anyone? Read on . . . 

  • The normal pH of the water in Portable Farms® Aquaponics Systems ranges from 6.5 to 7.2 for ideal growing.
  • Basil enjoys a very wide pH range between 5.1 (strongly acidic) and 8.5 (alkaline) with a preferred range of 5.5 (strongly acidic) to 6.5 (mildly acidic).
  • The roots of herbs enjoy being well-drained between watering cycles.
  • Portable Farms® Aquaponics Systems allow for full sun or the option of grow lights so herbs and vegetables can be grown year round which is ‘out of season’ in many areas and owners may collect top dollar for crops from local customers.
  • Basil seeds grow well in rockwool or Oasis Horticubes.
  • Basil plants may be placed on 8 inch centers and planted off-set in each row within a grow tray allowing for ample room for lush growth for each plant.
  • The root systems for basil do not spread out and are not complex root systems which makes for consistent and easy water flow throughout the grow bed during watering cycles.
  • The basil plant usually grows to a height of 18 to 24 inches and produces many offshoots for harvest per plant.

You can cut back basil two-thirds of the entire basil plant twice before replanting the basil to begin the process again. This extends the harvest of the basil leaves and provides more cash-value crops instead of a one-time ‘grow and harvest cycle’ like lettuce. Basil can also be raised in batches and sold to customers as entire plants.

  • Since one plant will produce for four months (after a two-month initial growth), you would only replant new basil plants every six months and be continually harvesting during each four-month harvest cycle.
  • Each 40′ tray will grow 450 basil plants (on 8″ centers) which allows for 900 basil plants per year grown in a single tray. These 900 plants allow two cuttings each which can be sold to local consumers at wholesale or retail prices in your area.

Bonus – Pesto Recipe We Use When We Harvest our own Fresh Basil

We cannot count times the many times we’ve invited friends to sit with us to enjoy an entire meal of fresh pesto sauce made from our own basil that was spread thick on hot homemade whole-wheat bread and served with sliced, freshly-harvested tomatoes from our own vines in our Portable Farms® Aquaponics Systems. It’s a real pleasure to share healthy and simple food with friends. This is our definition of ‘the good life.’

Portable Farms® Pesto Sauce – Fresh off the Vine

This recipe makes about 2 cups. If you plan to freeze the excess pesto, avoid adding the crushed garlic to the recipe and wait to add it until you thaw and serve the pesto because the garlic can taste bitter after freezing.

Ingredients List:

  • 8 cups fresh basil leaves, torn off vine (discard the stem/vine)
  • 1 cup freshly grated Parmesan cheese from a deli or fine store (don’t use the powdered Parmesan you shake out a canister for pasta)
  • 3 cups of pine nuts – slightly oiled and then toasted brown in an oven for 20 or 25 minutes
  • 3 garlic cloves, crushed
  • ¾ to 1 cup extra-virgin olive oil (depending on how thick you like your pesto sauce). If you plan to freeze your pesto for later use, do NOT add olive oil until you defrost.
  • 1 teaspoon sea salt
  • ½ teaspoon fresh black pepper


  • Place basil, ½ of oil, cheese, pine nuts, and garlic in a food processor. Pulse several times, until well chopped.
  • With machine running, quickly add olive oil in a steady stream, allowing pesto to mix blend and become cohesive but don’t over blend. Process until desired consistency is reached, season with salt and pepper, and serve. Again, if you plan to freeze your pesto for later use, do NOT add olive oil until you defrost.

Free Visual Tutorial to Build an Above-Ground Vegetable Tub Garden

Colle Davis, inventor, Portable Farms Aquaponics Systems

Grow Food in an Above Ground (movable) Tub

This page offers (free) suggestions and a visual tutorial for building an above-ground garden, often referred to as a raised bed. 

In the past 24 hours, June 15, 2020, Colle and I have built a small raised-bed garden to show you how to grow food.  This is a great family project with tasks for every member of your family to join in the fun.

The cost of this garden was approximately $100 for the materials. You can prepare the parts and then assemble it anywhere that receives six hours of direct sunlight. Some vegetables require less sunlight, but most like lots of sunshine.

We realize many folks may not be able to afford one of our aquaponics systems right now, but perhaps you can build one of these gardens at home, or consider building several in a community garden to grow food to feed families during this pandemic crises and high unemployment.

This grow tub is 2’x2’x8′ and is built near our kitchen door off our driveway and receives many hours of sunlight.

Personal note: We live in a very dense forest with 100′ trees and there are very few places with direct sunlight. (Robin Hood and Friar Tuck pass through our property quite often and wave at us from our driveway.)

In the final image (below) you’ll see we planted some tomatoes and basil to start our garden but we’ve also planted carrot seeds, radish seeds and many more basil seeds. 

Here are the layers necessary for building an above-ground tub garden.


Picture Tutorial for building your own above ground tub garden.

1. A few bag of garden soil.

2. Two sheets of 10′ metal sheeting and ten pieces of 8 foot 2’x4′ treated lumber. Avoid contact with the treated lumber and use non-treated lumber on the rim of the tub.  

3. Build a simple 2’x8′ frame for the metal sheeting and then screw the metal sheeting to the lumber. Build the two frames for the end pieces 2’x2′.

4. Move the grow tub components to an area that receives six-hours of direct sunlight that (preferably) has access to water or you can carry water in a bucket. 

5. Connect the side panels to the end panels using 3 inch screws. Notice the end pieces are longer to nail through.

6. Fill the box with dried wood-branches and logs. They will ‘settle’.

7. Add mulch. Our neighbor gave us access to his mulch bed of leaves. These leaves have tremendous nutrient value. 

8. Spread the mulch on top of the branches and logs and push the leaves into the spaces until the bed is even. 

9. Phyllis Davis and Scarlet watering the mulch and dried branches.

10. Next, we spread a layer of dried leaves mixed with grass clippings and some twigs to act as another nutrient base.

12. Then, we spread some garden soil on the top for planting.

13. Next, we leveled the soil to prepare the garden for planting.

14. Finally, we planted two tomato plants and a basil plant in our new garden and planted carrot seeds, radish seeds and more basil seeds. We cannot grow ‘root vegetables’ in aquaponics so planting carrots and radishes in soil is a big adventure for us. 

We’re not finished yet! Next, we plan to put bird netting around the farm to protect our vegetables from the deer, squirrels and birds that live near our house.  Stay tuned for our additions!

40 day after planting. Basil. Tomatoes. Radishes. Carrots.

June 25, 2020: Today, we finished a much larger above-ground garden for plants that do not require trellising (tomatoes, beans, cucumbers). We’ve relegated this garden for a variety of lettuces, Swiss Chard, basil, carrots, bok choy.

This garden weighs about 2,000 pounds because it’s layered with large tree trunks and branches,  several varieties of nutrient-rich mulch, grass clippings mixed with twigs and then top soil. 

Similar to the smaller grow tub behind this one, we will provide a bit of cover to protect it from the heavy rains we receive in Virginia and we’ll surround it with bird netting to protect it from the deer, birds and squirrels who share our land.