A lot of people have asked about fish farming and also how to maximize garden space, and while such topics are normally approached separately, in this particular case, the solution is combined and comprehensive, thus, so is the explanation and the instructions for how to build it.
It is indeed possible to build a combination fish farm and vertical farm together, each continually “feeding” the other in what is for all intents and purposes, a complete micro-ecosystem.
The Fish Farm
For the actual fish farm, it is recommended to be at least fifteen feet per side and built in a true square. This will allow for easier construction of the foot farm that will be built atop the fish farm, while at the same time allowing plenty of room for sunlight to hit all of the plants, and allowing the farmer to build an adequate stairwell access inside the foot farm and over the top of the fish farm.
It is also ideal to have the fish pond at least five feet deep for aquacultural and agricultural security in systemically sustainable developments. In short, a rather small swimming pool or a rather large “hot tub” style structure should be built.
This fish pond structure should have at least one drain pipe in one corner of the bottom, replete with a threaded cap that will allow for the complete drainage of the fish pond from time to time, as may be needed for harvesting and/or for cleaning the fish pond.
Furthermore, the concrete or cement for the flooring should be sloped down towards the corner with the drain pipe, allowing for the waste from the fish to flow down into this corner, again, as much for ease of cleaning as to ensure that the water will be emptied out completely during the draining process.
The Vertical or Foot Farm
The vertical farm can be built in any of a vast number of configurations, each and every one which can cover entire chapters in books, and far too involved to establish definitively in a single article. My personal preference has always been a gently sloped “flower box” running up alongside all four outer edges of the fish pond, almost in the same fashion that a car ramp would lead directly up to the roof of a garage.
I tend to keep these about one meter or just over three feet in width and about one foot in height, allowing for me to access the side or the center from either the platform inside and over top of the fish pond or from a mobile ladder along the outside of the vertical farm and fish pond.
This configuration is my personal favorite because it minimizes the need for hose for the drip system while still exposing all four sides to a sufficient amount of sunlight and also allows for easy access to the literal and figurative fruits of my labor, without having to trample or compress the soil.
There are a great many more intricate and fancy designs for those who want to get more involved with the process, each with their own individual strengths and limitations. There are numerous resources available online regarding foot farming and vertical farming and it is never a bad idea to be well informed.
It is important to note however, that the materials used for the construction will constantly be exposed to both sunlight and moisture, allowing for an excessive growth of foreign algae or other detrimental growth that can damage the materials.
Care should be taken to select the proper materials, though these will vary depending on the local environment as well. Local nurseries may be an invaluable source of information and a cup of good coffee and a box of donuts taken to a nursery in exchange for some answers may be a very wise expenditure.
For the soil, I use fertile top soil as a base … which may sound contradictory but it is not. The top soil is generally alive and well enough to support the compost and effluent mixtures that will be fully digested and used for the growth startup. The drip system is also laid in over top of the top soil base. The soild should be generated within the Philippine Permacultural Institute, a byproduct of the solid waste effluent from the waste to energy generation and large scale livestock growth.
This will, over the course of time, mix the added soils in to the top soil base and provide a much more fertile growing ground. I use an old barrel composter to compost the organic waste I generate, then let it rot for a while longer in a worm farm before mixing it with other effluent to create what will be used for the top soils.
Experimentation is rarely a bad thing, though care should be taken not to include non-organic matter anywhere into the mix. This mix is then laid out generally over the drip line in the top six inches, the top soil already covering the bottom six inches or so of the foot farms.
The heaviest 12 volt DC water pump or sump pump that can be found should be purchased. An aerator is technically, not an absolute necessity, though the author has always included an aerator in his constructions and recommends them, especially for the people building such a structure for the first time.
The twelve volt pump should be strong enough to push the water up to a height of at least fifteen feet, or to the maximum possible height on the top platform of the foot farm built on top of the fish pond.
At the top of the system, the container for the water should be placed high enough to allow for the water to drip down through the entire structure of foot farm or “flower boxes”, ultimately dripping back into the fish pond in the form of now-filtered water and providing for more aeration at the same time.
Bear in mind and remember, that this container is going to weigh much more than the foot boxes and may require additional support to prevent it from collapsing and destroying portions of the structure on the way down.
It may also be necessary to purchase a small solar panel if this system is to be run completely off the grid, or it can also be hooked up directly to a twelve volt battery bank if such a system is available. While the system can be built on standard residential electrical systems as well, it is understood that a majority of people living wholly off the grid will not have such electrical supplies readily available unless they are already well established, in which case the only things that would change would be the power supply and the pumping system. There should be no reason to purchase costly power inverters or other more expensive components that salesmen will inevitably try to convince you to purchase.
Vertical Farming or Foot Farming
The width of one meter, generally allows for the inclusion of plants to be introduced four wide, leaving at least six inches between rows. More traditional farming requires substantially more spacing between the plants largely because tractor wheels must fit between the rows. Some of the more bushy plants like tomatoes should be planted no more than three wide, while straighter plants such as okra may be planted four wide with no real need for concern.
Do not be afraid to top the plants (or to cut off the tops) as the plants grow too tall. Cutting off the tops will allow the root systems to shed some of their stored nutrients back into the soil, and by and large, most plants will bush out rather than growing more upright.
(Note: This does not usually hold true with corn, okra or other plants that grow on a singular, vertical stalk)
However, if you have selected your plants wisely, you should have a space that is adequate to at least supplement your dietary needs. Furthermore, unlike the more traditional hydroponics systems, these plants and their “fruits” should be packed full of healthy vitamins and minerals, providing you with a much healthier alternative to store bought goods.
For the beginners in such an arena, I generally recommend the American Bluegill as the ideal fish for such a structure. Bluegill thrive, even in small, frozen ponds in the wild and adjust very well, even in large numbers in relatively small spaces, as long as the water is well aerated and there is a means to provide food to the fish for their consumption.
The second fish of choice would be tilapia, another very hearty breed. However, like with the actual structure itself, care should be taken to make the best selections based on local environmental and weather conditions, and again, it is never a bad idea to seek out local experts to help fill in any blanks or to answer any questions before construction begins.
Let us know what you think please!