Pond Filter Flow Calculator (Manual Calculation)

Step 1 - Establish your pond volume

• Circular Ponds
  Diameter x Diameter X Depth (meters) X 785 = Volume in litres

• Rectangular Ponds
         Length x Width x Depth (meters)  x 1000 = Volume in litres

• Odd shaped (Such as Kidney or rounded corners)
         Average Length x Average Width x Average Depth (meters) x 800 = Volume in litres

• Triangular
         Length x Width x Average Depth (meters) divide by 2 x 1000 = Volume in litres

Example A rectangular pond 4 meters average length x 3 meters average width x 70cm average depth

                      Pond Volume: 4.0 x 3.0 x .7 x 1000 = 8,400 litres

Important If the sides of the pond are not vertical but tapered, reduce the volume by 10%
 

Step 2 - Pick your correct flow

Please make a note of your pond volume now. Now apply the pond volume to the chart below, using the fish stocking and sun situation of your pond to determine the approximate water flow required to maintain a healthy environment for your pond and it's inhabitants.
 

Choose the fish stocking that best suits your future fish stocking (allow a little extra for growth)

*Fish when measured end to end                   Special note - The more plants the better
 

Armed with the pond volume and fish stocking, add the other factors, sun shade etc

Pond in shade

Also allow for pond depth, your location and hose

If the pond is

• less that 300mm deep add 75% to the flow 

• between 301 & 450mm deep add 50% to the flow

• between 451 & 600mm deep add 25% to the flow

If you live in

• Tropical (Qld, NT or northern WA) add 35% to the flow 

• Sub tropical (Northern NSW) add 25% to the flow 

• Temperate (NSW, SA, VIC, Southern WA) add 15% to the flow

Hose length and diameter

If your total hose length is over 4m, or your waterfall is over 500mm, or if you have an existing hose that may be too small and can't be replaced, it may now be the time to either:

1. Fill in one of our e-mail help forms and let us do all the calculations for you

2. Give us a call 1800 607 388 for expert advice

Step 3 - Choose your filter

You now have the ideal flow through the filter in litres per hour for a healthy pond.

Now you need to decide what type of filter your require.

Always choose the filter first.
The horse must be ahead of the cart, so the filter must first be chosen before you can choose your pump. On each filter page there is a section named "suitable pumps"

(Remember your ideal flow through the filter will be needed)

Click one of the links below. You can sort through our range of filters very easily using a table in order to select one that suits your flow requirements.

Select your Pressure Filter

Select your Gravity Filter

OR

Jump straight to our selection of Filter Pumps* 

*Please ensure you have selected your filter before you choose a pump

How we established these figures

The above quick reference calculator represent the approximate circulation required for a pond in Australia using average calculations.

When making the above calculations we have taken into account average Australian climate, average pond plants, average pond depth (on the shallow side), flow loss through a filter etc. These circumstances may vary depending on the specifics of your pond and this chart should be used as a guide only, not a guarantee.

Special note:

Please use this chart as close guide only, the only way to exactly choose a pump and filter is by using all your specific and exact factors, the above if used correctly should get you within 10 - 15% of a perfect outcome. In doubt either fill in one of our e-mail help forms or call 1800 607 388.