What is pond pump head and what Does maximum head Mean?

Why Is Maximum Head Important When Selecting The Right Pond Pump?

Pond pump head is important and is defined as the amount of pressure that your fish pond-pump needs to produce in order to be able to run the waterfall, fountain and other pond components. The majority of water pumps are Submersible Pumps and have an impellor that spins very quickly. The rapidly spinning impellor creates pressure due to centrifugal force, hence the common name "centrifugal pond water pump". The impellor rotates at a consistent speed thereby producing a constant amount of pressure that is used by the water pump to supply your bio filter, fountain etc.

The pressure generated by your pump is used in two ways

  • Either to pump a larger quantity (volume) of water to a lower head or
  • To pump a lesser volume of water to a greater head.

A practical example of how to understand the term "pond pump head"

  • Attach a 10 ft (approx) length of pipe to your submersible pond pump.
  • Place the pump in your pond and hold the pipe at the pond surface ... water flows out of the pipe at a high rate.
  • Gradually lift the length of pipe vertically above the pond surface ... you will notice that as you lift the pipe higher the level of water coming out of the end of the pipe reduces.

Pond pump head & 3 tier waterwall diagramPressure and head are the same thing

Head developed by the pond pump in practice refers to the height to which the submersible pond pump is able to pump water to. Head is usually a measure of the distance between the pond surface and the waterfall inlet ... the example opposite shows a pond pump powering water to the top of a 3 tier waterfall. In order to choose the correct pond pump for your water gardening project you need to know the correct pond pump head for your particular system. Without this you can't specify the correct pond-pump to use. Feel free to use my Total Pump Head Calculator to help with the math.

We now know that the higher the height to which the pond pump has to force water the lower the volume of water output. The only way the pump can generate more pressure is to reduce the water flow i.e. a higher flow means less pressure (pump head) needed by the same pond pump. You will also need to know what the Pond Pump Flow is.

It is critically important to understand the relationship between water flow rate and pump head when choosing the correct pond-pump to use in your system.

What is meant by the term maximum head?

It is a term used by manufacturers that in essence shouldn't be because at maximum head a pump is useless, as the level of water coming out of the end of the pipe is NIL ...  the centrifugal energy (pressure) produced by the pump is 100% consumed in attempting to force the water to the desired height. The pump isn't powerful enough to push the water any higher.

Pond pump head loss can sometimes be overlooked but not always

Just as a ball that is rolled along the floor will eventually stop, due to resistance (friction) the same applies to pond water as it is pumped through lengths of piping to the biofilter, waterfall etc. This is particularly true in situations where the pond water is forced through T connections, valves, UV sterilizers and other fittings. This is referred to as the pond pump head loss or friction loss.

To be able to correctly specify the total pond pump head for any pond environment the pond pumps head loss should be considered. However in small backyard fish ponds using short lengths of pipe and with minimal bends and fittings this can be overlooked, providing:

  • You don't use pipe that is less that 1" thick.
  • You don't use pipe that is more than 10 feet in length.

Hint:  Whenever possible use ribbed piping as it doesn't restrict your fish pond pump's flow when bent to form curves or bends. It is almost impossible not have any bends or curves in a pond environment. In my opinion it is better to go for a slightly more powerful pump than you need as this reduces the workload on a smaller pump and will also more than likely increase the pond pumps longevity. Remember as stated earlier in this article you need to know what Pond Pump Flow is needed for your fish pond. Pump flow can be affected by whether or not you operate a waterfall, keep koi or other fish or if you purely have an aquatic pond. The next bit of knowledge required is how to read a Pond Pump Curve to help you determine the correct specification required. Pond Pump Reviews for a full list of all filter pumps, fountain pumps, solar pumps, submersible pumps and pumps for professional koi pond applications reviewed on this site.