How to choose a Submersible Pump

Are you a recent garden enthusiast and recently found the need for drainage and/or irrigation from a well?

Or are you a maintaining a Koi pond and need ways for water circulation?

Or are you in construction and need to find ways to remove water from foundations, tunnels, and other excavations pits?

A submersible pump would be your answer.


Operating principle of a submersible pump:

A submersible pump is a centrifugal pump fully submerged in the liquid or medium and operating in a vertical position (hence submersible). The position of the impeller accelerates the liquid and causes the liquid to be lifted by the pump stages (if any) and finally through the outlet. Typically, this is used to push fluid to the surface and are used in many residential (drainage / sewage) or industrial (oil well / borehole) uses.



Priming: Because the pumps operate below the surface of the fluid being pumped, they are in effect, self-priming.

Cavitation: Because the pumps are fully submerged, there is little risk of cavitation

Efficiency: Less energy is required to move fluid through the liquid path of the pump as there is positive fluid pressure at the inlet of the pump from being submerged.

Noise: Being submerged, these pumps are very quiet in most applications.



Accessibility: Submersible pumps are not easily accessible for maintenance as they are submerged in water, especially in sump or deep well applications. This makes it difficult for companies to perform preventive maintenance, in many applications, submersible pumps are left to run until they break down before being replaced.

Corrosion: Due to the submersible pump being submerged in liquid, its prolonged exposure to will eventually lead to corrosion. Submersible pumps are often used to handle liquids are corrosive and/or abrasive. Over time, seals may encounter damage or corrosion, causing leaks and damage to the motor. To counteract corrosion these pumps need to be made of anti-corrosion and if possible, rust-proof materials for longer pump life. Thankfully, even our most basic Leader Pumps range is made with such materials.




Nature of Liquid being pumped:


Particle Size

Are you using clear water or dirty water? It is important to note that certain impellers are only constructed to take particles up to a certain size. Generally, if there are particles with a diameter up to 5mm, the liquid is considered clear water and such submersible pumps are easy to find. However, if your pond or sump consists of sand or small algae parts, you may require a dirty water compatible submersible pump which handles up to about 30mm particles in diameter. Thankfully, our Leader Pump Range has you well covered with our Ecovort Range.

Require heavy duty units which can handle even larger solid particles for industrial purposes? Our Barnes Pumps’ Effluent Submersible Pumps Range is well suited for heavy duty high performance with the ability to handle up to ½” of solid particles.

For even more troublesome solids for wastewater applications, check out Barnes’ Blade Grinder Pumps and Sithe Chopper Pumps to meet your every need.


Types of Fluid

Always check with us on the fluid you are pumping, particularly if your fluid is any of the following:


    1. Corrosive, flammable or explosive substances
    2. Grease and Oil
    3. Salt Water (which requires special construction materials – please see here for more information)


Capacity Requirements




The more water you want to pump, the higher the capacity of the submersible pump should be. For ponds and water features that are bigger in size, you would want a submersible pump with a higher flow to circulate water around your pump.


Total Dynamic Head Required Depth of your Sump / Well

This is generally determined by the Total Dynamic Head which is the head required to elevate the liquid and friction head loss. For the purposes of simplicity, we shall assume that friction loss is negligible, and the Total Dynamic Head should be the lowest point in which fluid is being drawn down from your sump or well to the highest vertical fluid point above which the fluid will flow to.



Do make sure your electricity source has enough power to meet the needs of your pump. Generally, your flow and pressure are directly proportional to your power consumption (assuming your friction loss in piping is negligible and your flow is efficient).



Please be aware of several factors if you are intending to install your submersible pump without our assistance:


    1. Electrical Connection
        • Please verify that the pump nameplate, amps, voltage and phase match the control box and power supply. Incorrect voltage or phase can cause fire, motor, and significant control damage.
    2. Correct Rotation of the Impeller
        • Please ensure that the impeller rotates in a counter-clockwise direction (viewed from above). If the impeller is rotating in reverse with a three-phase motor, consult us to switch the power leads to correct the rotation.

Still unsure on (1) how to size up your pump for your application or (2) how to install your pump?

Contact us if you are looking for any solutions relating to the following:


    1. Residential Irrigation
    2. Sump / Deep Well
    3. Garden Irrigation Drip/Low Flow
    4. Hydroponics
    5. Rainwater Harvesting
    6. Providing Water Supply from Shallow Wells
    7. Pond Circulation
    8. Fountains and Waterfalls
    9. Drainage of clean Water
    10. Drainage of dirty Water
    11. Wastewater