The water pump in an aquaponic system is one of the most important components in the system. It circulates the water which passes through all the components in the system. If the pump stops, it can stop the entire operation of the system.
Proper pump placement is crucial when installing an aquaponic system.
It is recommended that the pump be placed in the sump tank which should be situated below the point where the water exits the aquaponic plant system. This type of Aquaponics system is known as CHOP – Constant Height One Pump.
An aquaponic system requires constant water circulation in order to have the full functionality of the components within the system. Without the pump or even with partial functionality it can have an adverse effect on how well the system functions.
See our complete guide on aquaponics and what you need to know to run a successful system.
Pump placement is critical and having it placed in the right place can have multiple benefits for you, and the aquaponic system. In this article, we delve into all the benefits of having the pump placed by itself at the lowest point in the system.
Why Should the Pump be Placed in the Sump in an Aquaponic System?
An aquaponic system requires a water pump to recirculate water in the system.
The water in an aquaponic system carries the heavy waste material from the fish tank to the mechanical filter where most of it is removed.
The water then flows to the biofilter where the bacteria converts the ammonia released from the heavy waste into nitrites. The nitrites is then converted to nitrates within the biofilter.
This two step process is called Nitrification.
The pump should be placed in the sump.
The sump is a separate component in an aquaponic system that houses the water pump.
Reasons for Housing the Pump in the Sump
- Having the pump with the fishes can cause smaller fishes to to be sucked into the inlet of the pump which will cause the pump to stop pumping.
Apart from the fish dying the entire system would stop functioning. The system does not stop functioning immediately. The water in then the mechanical filter, biofilter, and the grow beds will be at a stand still.
The plants will continue to use the available nutrients until there is not more.
This is a good thing since it gives some degree of time to rectify the problem.
- Placing the pump in any other place other than the sump will be impractical since firstly you would want to have only one pump in your system to reduce power consumption.
With having one pump in an aquaponic system you would want to place the sump at the lowest water surface in the system since it’s the pump which does the work in raising the water up to the fish tank and then to flow by gravity to the rest of the system.
The lowest water surface is usually where the plants are being grown eg. grow beds, DWC or Flooded pipes. Therefore the pump should be placed about one foot lower than the point where the water exits the plant system.
This would allow for the pump to have maximum possible output since the head height which the water is being pumped to would be very small.
This type of aquaponic system is called the CHOP system, meaning Constant Height One Pump.
Having this kind of gravity flow also promotes water agitation which increases the concentration of dissolved oxygen in the system.
What Size Sump is Required for an Aquaponic System?
The size of the sump should be large enough to hold the pump, the connected piping and the excess water from the system in the event the pump were to stop.
For example, a 400 GPH pump should be placed in a horizontal 15 gallon sump. Bigger pumps would require a larger capacity sump container.
You should also be able to place your hands into the sump to make adjustments or to even clean the pump.
The sump should also be fitted with a drain out connection for cleaning when the system is down.
Here is an article which shows how to plumb an aquaponic system to always maintain a level in all the components even when the pump stops.
What Kind of Pump is Required for Aquaponics?
The recommended pump for an aquaponic system is a positive displacement, submersible pump with an induction motor.
One such pump is the Hydrofarm Active Aqua Submersible Water Pump.
(affiliate link from amazon).
This pump is recommended because it gave us many years of faithful service with our own aquaponic system.
This Water pump can be submerged in water because the electrical circuits are totally insulated from harsh elements such as water.
The heat produced by the motor is dissipated into the water which in turn cools the motor.
How to Choose a Water Pump for an Aquaponic System?
I have written an in-depth article explaining how to choose the right pump for your aquaponic system outlining the required sizing, pump placement and also price.
See the article here.