Feeding a Family of Five with a Portable Farm in 125 sq ft

Feeding  a Family of Five with a Portable Farm in 125 sq ft
by Colle and Phyllis Davis

How much food does a family of five consume in a year?

Starting with USDA data for a healthy diet and accepting that most carbohydrates will come from grains and root crops, the table vegetables for one person can be grown in 25 sq ft of aquaponics grow tray space. So a family of five will need 125 square feet of grow tray space or a Grow Tray 5′ wide by 25′ long.

A climatically adapted greenhouse that is 10′ by 30′ will feed the family of five year-round, forever. That space is only slightly larger than a modern living room. Some of the protein source for the family will come from the fish that are grown in the Fish Tanks of the Portable Farm and the settling tank waste can be used to grow other crops and fruits outside the structure. Plants love the nutrient-laden settling tank waste water and reward the Portable Farmer with exceptional crops yields. The waste water can also be added to compost to speed up the process.

The average family of five consumes one head of lettuce per day for salads, garnish or sandwiches. The lettuce is planted on 8-inch centers in the Grow Tray. The lettuce needs approximately 30 to 40 days from ‘planting to harvesting’ which means there will be 40 lettuce plants in the Grow Tray at all times. 40 lettuce plants require 27 square ft of grow space. Each time a lettuce plant is harvested, a new seedling is placed in the same space to be ready to harvest in 40 days.

What other favorite vegetables are enjoyed by your family? Zucchini, any variety of peppers, eggplant, basil, Swiss chard, kale, cucumbers or maybe you would like a little space beans or bok choy. Find the spacing needed on the seed packet and begin planning out ways to fill up the rest of the Grow Tray.

With 90 square feet to fill up, the space that is 5′ wide and 18′ long will be beckoning to you even in your sleep.

Here is the trick that is the hardest for new Portable Farmers to grasp: THINK AHEAD AND PLAN LIKE A FARMER! Refrain from planting all of the space at once.  That is 27 square feet of open space for lettuce will tempt you to fill it up. Don’t do it. Plant a new baby lettuce plant every day into the gravel. Yes, it will be incredibly hard to do until the entire Grow Tray is finally full and you can stop buying vegetables at the store. It will happen, be patient and know that you are doing the best possible planning for your family’s survival.


Skip to comment form

    • Ndegea Benjamin on 2019-12-28 at 8:49 am
    • Reply

    Are you in Kenya?

    1. Ndegea: We are in many places throughout Africa but not Kenya.

      We are having a Two-for-One Sale January 10, 2020. https://portablefarms.com/2019/hobby-farms-two-for-one

      Happy New Year!

    • Allie on 2015-06-29 at 6:01 pm
    • Reply

    Hi, I saw this post and find it fascinating! I wanted to look into the 25 sq feet of aquaponics tray from the USDA data, but could not find it. Can you please provide a link to the source? Thanks!

    1. Allie,

      The source is from our own research and that of several universities on the food an adult requires to be well fed and healthy. The reference in to table vegetables and we are very careful to not this does not include root vegetables or grains.


    • janis on 2014-02-27 at 10:14 am
    • Reply


    I wanted to know if there is some info with a list of all fruits and vegetables that you can grow in aquaponics also included with average time needed to grow and required temperature? Thanks.

    1. Every plant has different requirements for both time from planting to harvest and different temperature requirements so I cannot answer your question with a specific answer unless you’re more specific. We post pictures of the plants that we grow in our systems on our website. http://portablefarms.com/what-you-can-grow
      – Phyllis Davis

    • Rich on 2012-04-03 at 9:48 am
    • Reply

    Hi Collie:
    Wondered if it was possible to de-salinize the water from the fish tank to the plants however keep the fish waste to fertilize the plants.

    1. Rich,
      If you can figure out how, you will have solved a huge problem. No, we don’t know how to do that, yet.

      Colle Davis, Inventor

    • Rich Mathis on 2012-04-02 at 10:34 am
    • Reply

    I wanted to know if there were any Aquaponics systems which could run off of sea water and therefore raise saltwater fish?

    1. Rich,

      Tough to find salt loving vegetables. If you can find tomatoes, peppers and lettuce that will grow in salt water we will work with you to become rich.

      Colle Davis, Inventor

        • Cheryl on 2014-03-15 at 11:19 pm
        • Reply

        Sea weed is very good for you! Is it possible to grow sea weed and sea algae this way? Chlorella and sea greens are very expensive.

        1. Cheryl: We do not grow algae or seaweed in our systems because we use gravel as our grow medium and the two plants would prevent water from flowing through the system. – Phyllis Davis, Co-Inventor, Portable Farms Aquaponics Systems

Leave a Reply

Your email address will not be published.