Beckett pond pumps

Submersible pumps

Sump pumps & fish ponds

Pump head or pressure?

Pond pumps

Stream or waterfall pumps?

Pump power & kinked pipes

Measuring the flow rate first

Using 2 submersible pumps

Danner 1200 pump

Testing the flow for waterfall

Hozelock pumps

Fountain pump

Water gardening mistakes

Pond Pumps - pump power, pump head, and kinked pipes explained

The following information is important for an efficient garden pond system 

Every electrical pond pump is fitted with a motor of some kind. This motor will be rated in watts or kilowatts. This rating is a measure of the amount of energy the motor can produce at maximum power and 100% efficiency.

Another important consideration in your garden pond system is to make sure the delivery hose or pipe from the pump is not bent or kinked in any way. This type of restriction will result in reduced water flow and an overworked pump, because much of the power generated by the pump will be wasted and water is forced through a reduced opening.  A restriction can also be caused by algae building up inside the pipe

Think of a pond pump in the following terms:

Water is heavy, as you probably know if you've ever carried a bucket or two up a flight of stairs. Well a pump has the same challenge, especially if water is to be pumped up into a large waterfall arrangement. And any kinks or other obstructions in your pipes will only make your pump have to work harder to do its job.

Now let's take a look at how your pump operates in a pond environment. Normally you will want to pump water up to a waterfall, and when you do that, you will notice that the water flow is much less at this higher level then what is pump out at ground level. In fact, if your raise the waterfall level up high enough, no water will flow at all, because you will have reached the pump's maximum operating point, or "head."  In practical terms, you're trading pump volume when you want to lift water (which is heavy) to a height above the pond's surface.

This follows the principle that you can't get something for nothing. The pump will have to share its energy -- some flow and some lift. The more the latter, and the less of the former, and visa versa.

Every pump box will state a MAXIMUM HEAD and MAXIMUM FLOW rating 

You can thus see that any pump will share its energy ... some to flow and some to lift. The more the lift the less the flow and vice versa. Every pump box states MAXIMUM HEAD and MAXIMUM FLOW.  Here's what these two terms refer to:

MAXIMUM HEAD

The height at which flow STOPS ... eg if this figure is 6 feet then at a height anywhere between 0 and 5.9 feet there will be some, but different amounts of, water flow. However at 6 ft there will be NONE.

MAXIMUM FLOW

This happen at the level of the pond surface and is the flow with no pipe attached to the pump.

As you can see, the energy produced by pond pump is divided between flow (the actual mass) and the height (head) to which it must be pumped. In a real pond situation, this becomes a bit more complicated as water is forced through a pipe, or via a "T" fitting, bends in the pipe, fountain nozzle, or through a valve or other obstruction.  Some energy will always be spent overcoming friction losses in these parts of the system, so you need to take this into account when you calculate your pond pump needs. These are also known as "flow restrictions," and you'll need to remove or lower these restrictions when you can. 

You will get better pump performance if you do the following:

• Use the largest diameter hose or pipe you can find.

• Use the shortest possible pipe length.

• Try not to kink the pipe (a real problem when using thin-walled plastic hose or pipe).

• Do not use T pieces, Y pieces, or valves in your tubing if you can avoid it. 

• Prevent the build-up of algae inside the pipe by using NON-TRANSPARENT tubing. 

• If you use stepped connectors, cut off the smaller diameter steps.

 When calculating your pump needs, you must know the following three things:

1. Volume of water flow required

2. Height to which this flow must be pumped

3. Head (or friction loss) loss due to restrictions in pipe and fittings.

This last component is complex to calculate. In a typical pond situation, if you add 20% to the height you want to pump, you'll normally be okay. For more on this topic, read the waterfall pump article, and the pump head page.

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