Aquaponics is a sustainable method of growing fish and plants for food that mimics the environmental processes that happen in nature. It reuses the waste produced by fish in the system as a resource for the plants farmed, creating a symbiotic integration of aquaculture and hydroponics. The system has been hailed as a farming revolution, which is why many have started wondering whether it is possible to do aquaponics even without electricity.
Here is how to do aquaponics without electricity:
- Design an alternative aquaponics system.
- Set up a fish tank.
- Prepare a media bed.
- Construct and install an alternative pump system.
- Cycle the system.
- Add fish to the aquaponics farm.
- Add plants to the aquaponics farm.
- Maintain the aquaponics system.
Although electricity is used to power many processes in aquaponics, its primary purpose is to run pumps used in system cycling and aeration. Read on for the complete guide on how to do aquaponics without electricity.
1. Design An Alternative Aquaponics System
You need to design an alternative system to account for a zero-electricity aquaponics system’s primary challenges. You must carefully develop your system to minimize the fallout of these problems before you set up your aquaponics farm to ensure that you do not run into problems when you add life to your system.
These problems are:
- Lack of water flow.
- Low aeration.
Therefore, you must design each part of your aquaponics farm to solve these problems to some degree. The next section of this article describes practical solutions to solve the above issues.
Lack Of Water Flow
Energy needs to be added to your aquaponics system for water movement to occur. The water needs to move from a source to the fish tank to the grow bed and back into the fish tank. This process is called cycling and is a necessary part of aquaponics systems as it enables essential resources to get to all life in the aquaponics farm.
However, an aquaponics system without electricity for pumps to run presents an obvious challenge. If gravity is used for water movement in the closed-loop system of aquaponics, you will need additional energy to move the water up from the lowest point to the highest point in the system.
This energy gap can be closed by using a pump that doesn’t use electricity, an alternative energy source (like solar panels, wind turbines, or a stream of water), or manually scooping the water. You can also use a combination of these alternatives.
Your source should be a stock tank, as a freshwater source would prevent system cycling. The tank would serve as a reservoir for the aquaponics system and should only hold water cycled through the system.
The source should have a valve to regulate the water supplied via gravity but must be topped off using some means. The means can be the alternative pumps like:
- A bell siphon.
- A ram pump.
- A pump system made from PVC pipes.
Aeration is an integral part of aquaponics as fishes and plants need oxygen to survive. An aquaponics system without electricity to power its air pumps will need other alternatives to improve or manage the amount of dissolved oxygen in the farm.
Using the alternative pumps listed above will help aerate your system, but you may need to take some extra measures to ensure the farm does not fail. For example, you can add a venturi to your source tank and fish tank to enhance the amount of oxygen in the water.
You can also use fish species capable of surviving in water with low oxygen and high ammonia levels.
Drawbacks To Using Aquaponics Without Electricity
- The alternate pump systems might not work if they are not appropriately designed or installed.
- The system can fail if the stock tank is not filled regularly.
- Algae growth in the stock tank, fish tank, or sump tank can deplete the oxygen in your system.
- The fish can die if ammonia levels increase due to a build-up of fish waste.
2. Set Up a Fish Tank
A fish tank provides a place for the fish to dwell and is one of the most critical elements of an aquaponics system. Fish tanks used in aquaponics can be bought as a whole or designed and built at home.
The ideal size of your fish tank depends on the species and amount of fish you decide to rear. Now, given that you want to be operating in the absence of electricity, your aquaponics will need an unconventional pump system, which can only be efficient for small-scale farms. For this reason, it’s best to keep the size of the fish tank modest.
Your fish tank should also have a solids lifting outlet that sucks up solid fish waste and a T-fitting that prevents a build-up of a vacuum. The tank should also have a valve to prevent water flow during cleaning and maintenance.
Although most aquaponic enthusiasts may choose large barrels as tanks, you can purchase and use the Rubbermaid Commercial Foam Stock Tank (from Amazon.com) as a fish tank. It would make for an excellent alternative, as it is sizeable, durable and easy to clean.
Before adding any fish, you will need to set up the tank like a regular fish tank, treating the water and allowing it to cycle for a while. This process enables the essential microorganisms to thrive, ensuring enough to provide the minerals required to nourish your plants. The cycling process is vital, and the latter part of this article delves into cycling aquaponic systems without electricity.
You should also add a radial flow filter to your system. This filter will allow solid fish waste to settle and works using gravity.
The radial flow filter allows water to pass through its overflow mechanism and into the grow bed, and an installed venturi can enhance the oxygen level in the water. You can clean them by opening the bottom valve and adjusting water flow via connected valves.
Considerations for Choosing a Fish Tank for Aquaponics Without Electricity
The size of the fish tank will be determined by the species of fish you plan on rearing and the size of the system you want to install. Furthermore, the fish tank you choose might depend on what purpose you want your aquaponics system to serve, whether as a food source or as an aesthetic piece.
However, there are various factors to consider when selecting a fish tank for aquaponics to guarantee that it can provide a suitable environment for fish.
Here’s what you’ll need to consider when choosing a fish tank for aquaponics done without electricity:
- The shape of the tank. Although the shape of the fish tank has a minimal role to play overall, it should be considered in order to design the rest of the system effectively. The round and square tanks are the two most prevalent fish tank shapes used in aquaponics.
- The material used to make the fish tank. Because of its durability, lightness, ease of installation, no-hassle plumbing, and low cost, inert plastic or fiberglass is recommended for fish tank construction. On the other hand, metals are not employed in fish tanks since they rust easily.
- The color of the tank. It is preferable to use clear or light-colored fish tanks because they enable a more straightforward observation of the fish. Furthermore, white and light-colored tanks reflect the light away, keeping the water cold.
- The cover and shading on the fish tank. You can use fishing nets or agricultural nets to keep fish from jumping out of the tank and keep leaves and other debris out. The cover will help protect the fish from predators such as cats and birds while reducing algae growth.
- The media bed used for the aquaponics system. Fish tanks and media beds complement each other, which is why their sizes need to be compatible. Therefore, the amount of water in your system determines the size of your media bed and fish tank.
Finding the correct fish tank for your system can be challenging, but doing so is the only way to ensure your aquaponics farm thrives. Once you have purchased or constructed the perfect fish tank, be careful not to overcrowd it. Keeping the stocking density modest will make your system easier to handle and more resistant to shocks and collapse.
3. Prepare a Media Bed
Media-filled bed units are the most popular designs for small-scale aquaponics. Therefore, media beds are the most suitable setup for building aquaponics without electricity.
The technique’s medium supports the roots of the plants in media bed units while also acting as a mechanical and biological filter.
Your media bed, also known as a flood table, will serve as the enclosure for the plants to grow in. This enclosure will need to be constructed on a sturdy platform to support its weight. You can use either a big heavy-duty plastic tray or a wooden pallet crate to achieve this.
When constructing media beds, you can use plastic, fiberglass, or timber frames with water-tight polymer sheets on the bottom and insides. Some aquaponic farmers use plastic barrels, modified Intermediate Bulk Containers, and even disused bathtubs to create media beds.
The media bed can be filled up and emptied using a bell-siphon mechanism as described in the latter part of this article. You should also consider adding red wiggler worms to digest any remaining solid fish food or fish waste.
You can also have a constant flow mechanism in the media bed. However, bell-siphons present specific issues. A bell siphon might cause the media bed to remain full once the water flowing from the stock tank stalls, and a constant flow mechanism can slow the water flow, leading plants to suffer and eventually die.
However, tanks used for media beds must satisfy the following requirements:
- They must withstand the weight of water, plants, and growing material without collapsing.
- The tanks must be located close to the other components in the aquaponics system.
- They must be such that simple plumbing parts connect them to other aquaponics components.
- They must be capable of withstanding adverse weather conditions.
- The fish, plants, and essential microorganisms should be safe in the tanks.
- The tank must be made of food-safe material.
A rectangle with a width of roughly 1 meter (3.28 ft) and a length of 1 to 3 meter (3.28 to 9.84 ft) is the standard shape for media beds. You can build more extensive beds, but they will need additional support to carry their weight and may not be viable for aquaponics without electricity.
Longer beds may also cause solids to build near the water entry, increasing the likelihood of areas with low dissolved oxygen.
If you’re looking to practice aquaponics without electricity, you should put the media bed above the fish tank, as there will be no pump to cycle the water effectively. Additionally, it would help if you built a small, isolated algal bed on a surface close to the media bed. The fish tank should also be positioned in a way that would allow the water from the algal bed to drip slowly into it.
Choosing a Growing Medium for an Aquaponics System
There are standards and essential criteria that all applicable growing media must meet. Generally, the growing medium must have enough surface area while remaining water and air permeable, allowing essential microorganisms to grow, water to flow, and plant roots to receive enough dissolved oxygen.
The growing medium used in aquaponics must satisfy the following standards:
- It should have a large surface area for microorganisms to thrive.
- The growing medium should have neutral pH and be chemically inert.
- The medium should have good drainage properties.
- It should be easy to work with the medium in aquaponics systems.
- It should have sufficient space for air and water to flow within the media bed.
- The growing medium should be available and cheap.
- The medium should be as light as possible.
After you’ve set up the media bed, it’s necessary to fill it with your preferred media. Clay pebbles are pH neutral, pose no harm to your water, and retain moisture effectively. Furthermore, they are one of the most common media used worldwide for aquaponics.
Some other types of media you can use for aquaponics include:
- Volcanic gravel
- Limestone gravel
- Coconut fiber
The growing medium can take up around half of the entire media bed volume, depending on what you’ve chosen to employ in your system.
Therefore, the sump tank must, at the very least, hold the entire water volume contained in the chosen media beds. Additionally, the water to growing medium ratio will help you decide on the ideal size of the sump tank for the system.
Sump tanks are not required for all aquaponic farms. However, they can aid in the proper maintenance of your fish tank’s water levels. You can improve the aquatic habitat for the fish in your system by installing a sump tank.
Sump tanks collect all the water running from the stock tank and through the system. They should be large enough to hold the total water capacity of the stock tank plus any overflow from the fish tank, and the grow bed.
4. Construct and Install an Alternative Pump System
Pumps in aquaponics cycle the water through the farm and aerate the system. Seemingly, aeration can be solved by allowing water to flow into the fish tank under the influence of gravity, but you must find a way to move the water to the other components within the system.
Therefore, to do aquaponics without electricity, it’s necessary to develop or purchase an alternative pump system that can operate without electricity.
Here are three pump alternatives you can use to do aquaponics without electricity:
- A bell siphon
- A ram pump
- PVC pipes
These alternative pump systems are not the only viable methods to pump water and aerate your aquaponics system. However, they’re all thoroughly tested methods commonly used in most aquaponics farms that do not use electricity.
Using a Bell Siphon
A bell siphon is a simple pump system that automatically uses a few fluid mechanics rules to fill and drain the media bed in your farm. The siphon operations and their overall success depend on a steady flow rate going into the bed. However, bell siphons can be challenging and require special care to use effectively.
The components of a bell siphon are:
- Standpipe: The standpipe is a standard PVC pipe in a bell siphon. The water drains through it, runs through the bottom of the bed, and connects to the sump.
- Bell: The bell is made up of a PVC pipe with a PVC end cap on top and an open bottom that fits over the standpipe. The water flows into the standpipe inside the bell through two rectangular openings towards the bottom of the bell. Once the grow bed has been drained, a final hole is drilled a distance from the bottom to help break the siphon and allow air to enter.
- Media guard: A PVC pipe with numerous small holes bored into its sides serves as the media guard. The media guard keeps the medium in the media bed from blocking the standpipe while allowing water to flow freely.
The size of the grow bed and the source water flow rate will determine the dimensions of the standpipe, bell, and media guard used in this alternative pump system. The water source for a system that uses a bell siphon can be a stream or another steady alternative. This way, the water will flow into the system at a constant rate.
As the water fills the media bed, it will reach the standpipe’s top, where it will drip back to the sump tank through the standpipe. This process would result in a system with constant water height if the bell section of the bell siphon were not present. Instead, as the water flows through the standpipe, the bell, shaped like a hat, functions as an airtight lock, creating a siphon effect.
The suction starts the siphoning process within the bell component of the pump. As soon as you start the bell siphon, all the water from the media bed begins to flow through the standpipe at a quick rate while the bell maintains its airtight seal. The water draining through the standpipe in the bell siphon is faster than the fish tank’s continual flow rate.
When the water in the media bed has drained to the bottom, air automatically enters the bell’s base, stopping the siphon. The water slowly fills back up, and the cycle repeats itself indefinitely.
Using a Ram Pump
A ram pump, sometimes known as a hydram, is a hydropower-driven cyclic pump system. It takes in water at one pressure and flow rate and drives it out at a higher pressure and flow rate. The pump employs the water hammer effect to create a force that permits a portion of the water used to power the pump to be raised to a higher level than what it initially was.
The hydram is primarily used in areas with hydropower sources and a need to pump water to a destination higher than the source. The ram pump is especially effective in aquaponics done without electricity because it uses only the kinetic energy of flowing water as a power source.
A ram pump is made up of the following components:
- Inlet-drive pipe
- Outlet-delivery pipe
- Waste valve
- Delivery check valve
- Pressure vessel
The waste valve in a ram pump is initially open during operation while the delivery valve is shut. After that, the water in the drive pipe will begin to flow under gravity, increasing flow rate and kinetic energy until the waste valve is closed by the rising drag force.
A water hammer effect is caused by the momentum of the water flow in the supply pipe against the now-closed waste valve. This effect raises the pump’s total pressure, opens the delivery check valve, and pushes water into the delivery line.
Simultaneously, the water hammer effect caused by the waste valve generates a pressure head that travels up the supply pipe towards the source, where it is converted to a suction force that travels back down the pipe. With the newfound spring on the delivery check valve, this suction force drives the waste valve open, enabling the operation to resume.
However, keep in mind that you might run into a few problems when using a ram pump in aquaponics. The primary drawback is that setting up the pump requires a bit of technical know-how. Furthermore, ram pumps can only be used with existing moving water sources.
Using PVC Pipes
PVC pipes are an integral part of aquaponics, and you can construct a simple pump using a few inches of the material. Using PVC pipes to make an alternative pump system requires a bit of technical knowledge, but the device may not be as effective as the other pumps discussed in this article.
You can use a simple pump made of a piece of 8 to 10 cm (3 to 4 inch) PVC tubing with an elbow at one end in aquaponics.
A pipe measuring 8 cm (3 in) is placed into the elbow to connect a cap to the other end. The cap is then drilled with holes to allow water to flow through it into the pipe. The pipe’s cap is inserted into the lowest part of the tank’s bottom and kept there until the mineral-rich water in the pipe reaches the same level as the tank.
Afterward, place your hand over the pump’s end to produce suction, and lean the pipe out of the water, with the holes in the cap pushing against it to prevent any fluid from draining out. Lean the pipe until water pours out the other end and into the growing bed. Continue this operation until the water level in the media bed reaches the desired level.
Remove the board dividing the algal bed and media bed when the media bed is filled, and allow the water to flow into the algae bed. The algal bed aims to grow algae for the fish to consume while also removing extra minerals from the water before returning to the fish tank. This process reduces the chance of overpopulation of microorganisms in the tank, which would deplete the fish’s oxygen supply.
The system can be aerated by installing a grid of sticks in the media bed. This device will break up the water when poured into the bed. However, in this case, another device is required to sit beneath the discharge produced by the media bed and the outlet from the algal pool.
You’ll also need to spend a few minutes each day scooping water in and out of the fish tank to boost the system’s dissolved oxygen levels.
5. Cycle the System
You should always make sure your aquaponics system is healthy before adding fish and plants to your farm. The cycling process develops beneficial microorganisms in an aquaponics farming system and transforms aquatic waste into nitrates. These microorganisms and essential minerals are required for plant growth.
Cycling begins the moment you put up a new aquaponics farming system or restore an existing one. The process takes about 4 to 6 weeks with fish, but you may speed it up by directly injecting ammonia into your system.
The 4 to 6-week time frame is generally determined by the water temperature, which should be between 75 and 80oF (24 to 27oC). However, because the bacteria are slow to eat and reproduce at temperatures outside of this range, you must efficiently control the temperature of your system at all times.
6. Add Fish to the Aquaponics Farm
After setting up the pump and cycling the system, you can add fish to your aquaponics farm. As always, you’d first need to make sure the environment is at optimal levels by checking the dissolved oxygen level in the water. Fortunately, you can add a wide range of fish to your system, even though tilapia are usually the most preferred for most aquaponic farms.
You can also add goldfish, koi, pacu, guppies, catfish, or whichever species of fish you want to cultivate.
7. Add Plants to the Aquaponics Farm
Plants with a lot of leaves do well in aquaponics systems. You should have hardy plants that can live on low nutrient levels due to potential infrequent cycling. If you already have enough fish in the tank, you might be able to also cultivate plants, such as:
You can also add the following to your aquaponics farming system:
Planting seedlings is the best way to make sure your plants thrive. Place their roots carefully into the media bed, ensuring they extend deep enough to take essential minerals from the water.
8. Maintain the Aquaponics System
You will need to check the pH, ammonia, nitrites, and nitrate levels in the tank water as often as you can to ensure the system’s environment is at optimal levels. If you want your plants to thrive, essential mineral levels should be almost undetectable, and nitrite should be minimal.
Furthermore, the pH level of the system should be neutral, ranging from 6.8 to 7.0, which is great for all life on your farm. However, aquaponics systems can often need some adjustments in this area since the pH drops below 7.0 after the first cycle is completed. It would be best if you alternated adding calcium hydroxide and potassium carbonate to the tank in powdered form to increase the pH.
Setting up an aquaponics system without electricity is similar to setting it up traditionally. However, aquaponics without electricity require pump alternatives to cycle water through the system and aerate the farm. Bell siphons, ram pumps, and PVC pipes are all excellent alternatives that don’t require any electric power.
After the alternative pump has been installed, you can add water to the aquaponics farm, cycle the nutrient-rich fluid and add plant and animal life to the system. However, since DWC and NFT techniques need pumps to work effectively, you can only use media bed systems if you’re operating without electricity.