An aquaponic system depends heavily on the reliability of the power supply simply because the main components such as the water and air pump keep the system functioning.
An aquaponic system can be protected from a power failure by having a backup supply on standby to maintain the continuous operation of the system. Both the air pump and the water pump should be kept running to provide dissolved oxygen and maintain water circulation for the plants and fish.
Most aquaponic systems require nutrient-rich water to be circulated continuously within the system. This type of system is termed RAS (Recirculating Aquaponic System).
Plants depend on water circulation to get nutrients and oxygen to grow and the air and water pump facilitate this. Having a proper backup system to supply continuous power is critical to the success of an aquaponic system.
By knowing how to arrange and install a functional backup system you can ensure an aquaponic system runs even when there is a power failure.
However, there are a few things that are necessary to accomplish this and we are going to go through everything required to have that peace of mind when it’s most needed.
See our complete guide on aquaponics and what you need to know to run a successful system.
How Long can Fish Survive without Power?
Fishes can normally survive 4 to 6 hours after a power failure. However, this depends heavily on the amount of fishes there are in the fish tank.
Fishes, like all other living organisms, require oxygen for respiration and normal cell function. When there is a power failure, both the water pump and the air pump goes down.
This stops dissolved oxygen from entering the water stream which would be normally supplied by the air pump and agitation from the water circulation in the system.
Once the dissolved oxygen starts to deplete the fishes would start to become stressed as they realize something is wrong.
A good indication that the oxygen level in the fish tank is low is when you see the fishes gasping at the surface of the water. This is when you will know that your fishes need more Oxygen.
The Fishes move to the surface of the water because this is the only place where oxygen is entering the water. But this is usually not enough to sustain their oxygen demands and they eventually suffocate.
How Long can Aquaponic Plants Survive without Power?
Plants in an aquaponic system can survive 24 hours depending on the type of aquaponic system.
In aquaponics systems such as Grow beds and Deep Water Culture (DWC), plants can survive for a long period often outlasting the duration of a power failure because of the reservoir of water the plants and their roots have to draw nutrients from.
In grow beds and DWC systems, the plant containers are designed so that it holds water. So even if the pump stops there is always water for the plants to get nutrients from. This remaining water will keep the plants from dying during a power failure.
When designing an aquaponic system these types of systems can be used to protect the plants in the event of a power failure.
Other types of aquaponic systems may not be so fortunate.
Plants in an NFT Aquaponics system can survive a maximum of 8 hours. This is because the NFT system does not hold a reservoir of water for the plant roots to continuously draw nutrients for survival. The water drains out into the sump tank leaving the roots dry.
The plants will remain upright for 2 hours before the leaves start to wilt, after which everything goes downhill from there.
How to Keep the Fishes Alive during a Power Failure?
Fishes can be kept alive during a power failure by having a backup air pump to supply air to the fish tank. There are many types of backup air pumps which supply an uninterrupted flow of air in the event of a power failure.
When choosing a backup air pump you will have to consider both the size of the fish tank and the number of fishes there are living in the tank (fish density).
The fish density can have a big effect on how effective these backup air pumps work during a power failure.
If the fish density is high or you have a large fish tank you might have to consider using two or more of these backup air pumps simultaneously.
What to Consider when Choosing a backup power supply for an Aquaponic System?
A reliable power supply is as important to an aquaponic system as much as the nutrient within the water.
Electrical items such as lights, water pump, and air pump are typical in aquaponics and all carry our different functions which helps an aquaponic system to flourish.Â
A power failure can be one of the most detrimental failures in aquaponics which can cause the entire system to stop, literally.
In order to properly address the situation of power failure, you would have to consider a few things before setting up a backup system.
Before Installing an aquaponic backup system, you will have to consider factors such as
- Frequency of power loss
- Duration of power loss
- Quantity of power required
- How Often does a Power failure Occur?
The frequency of a power loss depends on your location, sometimes the power might be cut twice in one year or maybe once a month. Regardless of the frequency you should have something in place to protect your investment.
- How long would a typical power failure last?
The Duration of a power failure can directly affect the aquaponics system. Lets say, the power only cuts for 5 minutes whenever it goes out. This may not really be much of a concern since the fishes and plants can survive through a short period of no circulation.
If the power loss goes on for more than 6 hours at a time then you will have to ensure that the backup system is robust enough to allow for bumpless switching and continuous running during this period of time.
- How much power does the air and water pump require to run?
The size of the electrical components that runs the aquaponics system would give an indication on how much power is required and the length of time the equipment can run with the given backup power.
So let’s take a small aquaponics system for example. A 400 GPH pump @ 25W and a an 800 GPH air pump @ 18W, uses a total power of 43 Watts. Therefore you would need a backup power supply that would power these two pumps for at least 12 hours or at least for the duration of the Power Failure.
A backup power supply mainly consists of a bank of batteries connected to a power inverter to provide power during a power loss.
How do I Aerate my fish tank without electricity?
Oxygen can be added to a fish tank by agitating the water. Water agitation creates bubbles and allows oxygen to be easily dissolved into the water and this is what we term Dissolved Oxygen or DO.
Using this concept you can devise ways to add that much-needed oxygen to your fish tank during a power failure.
One such way is to dip out some water with a container and hold it up at a distance above the waterâ€™s surface and then pour it back into the tank, continuously.
This causes the water to be churned up, which creates bubbles similar to the way an air pump would.
This method works well for smaller tanks but soon becomes very tiring. But what else can you do if you don’t have a backup power supply or a backup air pump? Your primary objective is to keep your fish alive at this point.
Another way to manually add oxygen to your fish tank is to use a mechanical device such as a windmill. This can be used in outdoor aquaponics systems.
A windmill can use the energy from the wind to turn the windmill which eventually churns and agitates the water. The question you may be asking is, how will the windmill turn at night?
Well, the wind also blows during the night. It may not be as strong as during the day but it still does during the night.
The agitator, however, should be shielded from the fishes. Fishes can easily get caught in the propellers which can cause them to die and stop the windmill from turning.