Pond Pumps in Australia

Pond Pump Considerations

Research your Australian pond pump and water fountain and waterflow requirements on this site. From the smallest barrel to the largest pond, no water garden can survive very long without water movement. And for water movement, a pond pump is essential because it keeps the water circulating and the pond/water garden healthy.

A cascading, bubbling stream adds interest and serenity to the garden, while a waterfall can create a dramatic centre piece. Fountains, are aesthetically pleasing and provide the additional benefit of aerating the water, essential for providing a healthy environment for fish.

When selecting a pond pump, be sure to consider:

• litres per hour (LPH) of each pond pump
• maximum height that the unit will pump (known as head height)
• type of pond filter
• manufacturer's warranty
• power consumption

You get what you pay for and its advisable not to cut corners when choosing your pond pump - it may well cost you time and money to fix in the long run, as ponds can quickly become a green smelly mess if the correct equipment is not used.

For more help, see our main site : www.pondsupplies.com.au/pondshop

Calculating the litres per hour

To determine the litres per hour rate for your pond pump, there are a number of factors that must be taken into account to pick the right equipment.

1. The actual volume of your pond
2. The 'effective volume' (taking into account - Fish, pond depth & size, sunshine, climate etc
3. The maximum pumping height (head ) - taking into account elbows, tees, friction loss, hose size
4. Waterfalls & streams, tube friction loss (see chart below)
5. The weir rate for waterfalls and streams
6. Pond filter (if being used) see 'Filters' below
7. Power consumption (watch the watts)

Actual Pond Volume

1) Calculate actual pond volume

Next step is to convert actual volume to our base starting point.
Because basic pond circulation is based on a near natural garden ponds with plant zones, without fish you should take the actual volume and divide by 2, to give a pond circulation of once every two hours

So armed with a figure representing 50% of the actual volume, simply add the following additions.

2) Effective Pond Volume

To determine the correct equipment for your pond, the actual volume of the system must be adjusted to compensate for adverse environmental factors. This is easily done by working out the 'effective volume' of your pond taking into consideration such factors as, direct exposure to sunlight, shallow depth, fish, climatic conditions etc. The 'effective volume' of your pond is determined by adding the percentages listed below to it's actual volume

Pond Depth

Pond depth	Average pond water depth	Adjustment
	Small shallow ponds under 1000 litres	+ 50%
	less than 30cm	+ 75%
	31cm - 45cm	+ 50%
	46cm - 60cm	+ 25%
	over 60cm	+ 0
	Large ponds over 20,000 litres	Contact Us

Make a note of your Pond depth adjustment

Sunshine Factor

Sun per day (summer)	Average pond water depth	Adjustment
	Full direct sunshine	+ 25%
	75% sunshine	+ 15%
	50% sunshine	+ 10%
	25% sunshine	+ 5%
	Full shade	+ 0

Make a note of your Sunshine Factor

Koi Carp and Gold Fish

Allowance for Gold Fish, Koi or Turtle Stocking Level

Fish quantity	Average pond water depth	Adjustment
	Just a few gold fish or similar (up to 150mm* per 1000 litres)	+ 25%
	Light stocking of gold fish or smiliar (up to 400mm* per 1000 litres)	+ 50%
	Medium stocking of gold fish or similar (up to 800mm* per 1000 litres)	+ 100%
	Heavy stocking of gold fish or similar (greater than 800mm* per 1000 litres)	+ 150%
	Just a few Koi or Turtles (up to 150mm* per 1000 litres)	+ 50%
	Light stocking of Koi or turtles (up to 400mm* per 1000 litres)	+ 100%
	Medium stocking of Koi or turtles (800mm* per 1000 litres)	+ 200%
	Heavy stocking of Koi or turtles (greater than 800mm* per 1000 litres)	+ 300%

Make a note of your Fish stock allowance

Australian Climate effect on pond pumps and filters

Climate (location of pond)

Make a note of your Climate allowance

Water Filters and their Effect

Effective Pond Volume

Type of pond filter

Putting it all together - effective volume examples

Example 1

If you have a 6,000 litre pond, your base volume is 3000 litres the pond is 60cm deep and exposed to full sunshine in Southern NSW.
Your pump and/or pond filtration equipment would need to be increased by 65 % (25% pond depth + 25% sun per day + 15% climate). You would therefore base your selection on a pond volume of 4,950 litres.

Example 2

f you have a 9,000 litre pond, your base volume is 4,500 litres the pond is 35cm deep, located in full sunshine with "a light stocking of fish" and you live in a Tasmania. Your pump and/or pond filtration equipment would need to be increased by 125% (50% pond depth + 25% sun per day + 50% light fish + 0% climate) You would therefore base your selection on a pond volume of 10,125 litres.

Maximum pumping height

(total head)

For vertical lift

For a given pump, the higher water is pumped vertically - the lower the flow; at a given height the flow will be zero. The terms "head height" or "lift" are used to indicate this vertical height, measuring how high the water can be pumped for a particular application. Each pump has a published graph showing its flow rate at various heads. Waterfalls or streams have the added factor of friction loss created by the longer hose run required between the pump and the top of the waterfall or stream.

Friction loss - for waterfall or stream use.

Pumping water through tubing adds resistance, so an allowance must be made for friction loss inside the tube. However as the size of the tubing has a significant bearing on frictional resistance, the use of an undersize tube will increase frictional losses.

As a rule of thumb add 10cm of head for every 1 metre of horizontal tubing run

+ 10cm

An allowance for friction loss must be added to the vertical distance (in metres) measured from the surface of the pond, over which you will be pumping the water. The resulting sum will be the 'Total Head' that the pump will be required to lift the water. You should compare the flow rate that you require, to the flow rate that the pump provides at this specific head.

Elbows/Tee - The effect they have on flow rates

If you intend to have any tees or elbows in the plumbing system, you should allow for the loss of flow that an elbow or tee will create.

As a rule of thumb at least an extra 25% of head height should be added for each one.

+ 25%

Example

The vertical distance between the pond surface level and the top of the waterfall is 1 metre. There is 6 metres of tubing between the pump and the waterfall. Your total head is 1.6 metres.

However, if the more accurate tables below are used for the flow of 6,000 LPH you will see that the friction loss can vary between as little as 0.03 when using 1.5" hose up to a huge 0.34 when using 1" hose. In other words the jump is from 3% up to 34%.

Friction loss in hose chart

The chart below will show that there is a massive difference between flow and hose diameter. Doubling the diameter of the hose increases
the flow capacity four times -no wonder there is less friction per metre. For example 25mm hose is 490 square mm while 32mm is 804 and 38mm 1,256 square mm.

Hose Flow Rates

The tubing size required at the pump is determined by the maximum flow rate of the pump selected. It is important that the diameter of the tubing chosen is appropriate for the volume of water coming from the pump. A hose adapter or a combination of adapters is required to attach the hose to most pumps. Following are the maximum flow rates in litres per hour (LPH) for various tubing diameters:

If your pump appears not to deliver the amount of water it is rated for, perhaps you are using the wrong size tubing.

Recommended tubing sizes are listed for each pump that we sell. Please click on the pump model number for more details. The requirements of different pumps can vary and the above chart is meant as a guide only.

Weir rates for waterfalls and streams

Waterfall Weir Rates (waterfall rocks etc)

NOTE: These do not apply to to manufactured spillways as they have their own predetermined flow rates that are shown on the page of each product

The most important consideration in setting up a waterfall is it's appearance. The volume of water required to achieve different effects, from a robust waterfall to a modest trickle, will depend upon the width of the waterfall lip (weir) or stream and the material that it is constructed from. The chart below will tell you how much water is required per 10 cm of waterfall width to achieve different depths of water over the entire width of the waterfall weir. Once you have calculated the total head of the waterfall, it becomes quite easy to determine which pump to use.

Example

You have a 1 metre high waterfall (measured from the pond surface), and will have 4 metres of tubing run between the pump and the top of the waterfall. The total head is therefore 1.4 meters. To achieve a 7mm water depth over the width of a 25cm wide waterfall weir, you would require a pump producing 2,520 LPH (1008 LPH per 10cm x 2.5 (25cm total width)) at a total head of 1.4 meters.

How to Measure Flow Rate

This formula can be used to measure the flow rate of the pump you require.

With a container of known volume (e.g. a 25 litre bucket), measure the period of time in seconds taken to fill the container by the flow that you wish to measure . Then divide 3600 by the number of seconds taken to fill the container and multiply by the volume (litres) of the container. The result will be the flow rate in litres per hour.

Example: It takes 10 seconds to fill a 25 litre bucket.
(3600 divided by 10 seconds) x 25 litres = 9,000 LPH

You can also use this formula to decide how much flow you would like over a waterfall. Simply place a hose at the top of the waterfall and adjust the volume of water until you find the flow that you like. Measure this flow and you will have an idea of the volume required to get the effect you desire.

For Circulation Purposes (including Fountain Heads)

To maintain a healthy natural pond with no fish, experts recommend circulating the water at least once every two hours. This means that for a pond with an effective volume of 8,000 litres, at least 4000 litres per hour (LPH) must be circulated. Hence a pump capable of pumping 4,000 LPH or more at the total head of your project is required. This is the absolute minimum amount of water that you need to circulate.

Small & Shallow Ponds (up to 1000 litres approx.)

Due to the special requirements and unique circumstances found in smaller and shallow ponds, including most pre-formed units, we recommend you circulate the effective volume once per hour.

Example

If the effective volume of your pond is 600 litres, look for a pump that can deliver 600 litres at the total head of your system. If you are pumping up to a waterfall or cascade 70cm above pond surface level, you need to pump 600 litres at 70cm head. The head will be increased by the friction created by the tubing.

Pump Selection

Sizing a pump for a waterfall or a stream is usually quite simple. The first consideration is that the Effective Pond Volume is circulated at least once every two hours. This would be the minimum flow requirement. The second, and usually the most important consideration, are the characteristics of the waterfall. These include the amount of flow that you wish to see coming over the waterfall and the width of the waterfall.

Please take a moment to review how to calculate the total head requirements for your waterfall or stream.

Example

Assuming you want to operate a waterfall with a vertical head of 1 metre (vertical distance from pond surface level to top of waterfall) and you will have 3 metres of 20mm tubing between the pump and the top of the waterfall. Your total head will be 1.3 metres. The smallest pump that you should consider would be one that is capable of circulating half the effective volume of the pond at a total head of 1.3 metres. Assuming an Effective Pond Volume of 10,000 litres, the pump that you choose will have to be able to deliver 5,000 litres per hour at a 1.3 metres head. This is the minimum requirement for circulation purposes.

Hint: Place your pump as far away from the waterfall as possible to maximize circulation within the pond.

When operating a waterfall, another important consideration is appearance. Depending on the width of the waterfall lip (weir) or stream and your expectations, half the effective volume may not be adequate.

The next step is to determine the flow requirements of your waterfall to achieve the type of effect you desire. You may need to consult the waterfall weir chart for more details.

Hint: As a rule of thumb, 380 LPH per 25mm of waterfall/stream width will provide a good flow equal to a sheet of water approx. 9mm deep over a waterfall weir.

Example

Assuming the waterfall is 45cm wide and using the 380 LPH per 25mm guideline, you should select a pump that can deliver at least 6,840 LPH (380 LPH x 45cm width) at a 1.3 metres head (as calculated above). This is slightly more than the 5,000 LPH that the 10,000 litre pond in our example requires for circulation purposes alone but will result in a more aesthetically pleasing display. Within reason, circulating the effective volume of the pond more frequently will not harm the pond.

Once you have determined the volume of water that you will require, visit our online store and you can search our pump range by flow rates. In this example you would look for a pump in the 8000 LPH max. output range because you require 6,840 LPH at a 1.3 metres total head.

The final selection is up to you. Criteria would be initial cost, power consumption and manufacturer's warranty. The annual operating cost comparison figures on pond supplies website make it easy to determine which pump will be most economical to operate over the long term. Sometimes, a less expensive pump with a high power consumption will cost you more in the end.

Hint: Make sure your lower pond is large enough to accommodate the flow from your waterfall and the output from the pump . This will ensure an adequate water supply for the pump at all times and helps contain any splash that the waterfall may cause.

If a flow rate of half the Effective Pond Volume once every 2 hours is too much for your waterfall, we recommend to split the flow coming from the pump discharge by using a hose tee, and diverting part of the flow to another water feature or to the other side of the pond to maximize circulation. You may have to install a ball valve in one or both of the lines to control the amount of water going in each direction.

All that is left to do is to choose the correct size of tubing as dictated by the maximum flow rate of the pump you select. Recommended tubing sizes are listed for each pump that we sell. As each pump has different requirements, the tubing flow rate chart is meant as a guideline only.

Hint: If your pump does not deliver the amount of water it is rated for, perhaps you are using the wrong size tubing.

Progress

Choosing a pond filter

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