How To calculate pond volume for any shape of garden pond

All fish ponds need a bio filter to allow water in which fish live to remain clean and healthy. Pond fish pollute their own living space and we must help them clean it to prevent the goldfish or koi from dying. Know how to calculate your pond's volume and this will help pond biofilter selection as well as pump choice

Calculate your pond volume easily

General Information Pond Volume...

Any pond's volume is determined by multiplying the cross sectional area of the water surface by the average water depth.

For example if the area is 5 sq metres and the average depth is 1 metre then the volume is as follows

Volume = 5 x 1 x 1,000 = 5,000 litres

The method for any pond shape . Refer to the above sketch... TAKE ALL MEASUREMENTS IN METRES ( EG 20 CM = 0.2 METRES)

Go outside and take the longest dimension across your pond in both directions Take some graph paper and draw a rectangle equal in scale to the dimensions you have just measured Divide the rectangle into squares or rectangles each must be the same size record the number of squares in total (call this A) Now sketch the pond as accurately as possible using the same scale like the diagram above. 5cm per metre is a good scale to use All you have to do now is count the squares NOT covered by the water In practice it is easier to count YELLOW squares (partly covered) and WHITE squares (not covered) separately Estimate the yellow squares since some will be a half, or three quarters etc etc call this total of the fractions of partly covered squares B Call the count of the white squares C Measure the width and length of the white square or rectangle call these WS and LS - remember to use METRES according to your selected scale

Calculating surface area is now very easy and is done as follows:

STEP 1 . Work out A - B - C and call the answer D

STEP 2 . Work out D x WS x LS , this is the surface area covered by water, call this E

STEP 3 VOLUME = E x Average depth of the pond x 1,000 to get to litres

If you have a very uneven pond depth take a stick and measure depth in 10 different places

Add all depths up and divide by 10. This average depth .. MAKE SURE YOU USE METRES