Goldfish Ponds Part 3: Goldfish pond size
When you have got as far as picking the location for your pond and choosing between the different types of pond available, the next consideration is goldfish pond size. Obviously the size of your pond will dictate to a great extent how many fish you can actually keep within it, but there are other factors to bear in mind as well.
When browsing for pre-formed pond molds or working out exactly how big the volume of your pond should be, it is always important to calculate the actual volume of your pond rather than just guessing a rough goldfish pond size.
The different shapes and sizes that ponds come in can prove misleading, and lead the fish keeper to assume that their pond’s volume is actually larger than it really is at a glance.
Calculating the volume of your pond
If you are buying a pre-formed pond mold, the volume of water that it holds should be made clear on the packaging, as trying to calculate the volume of an irregular shape can be complicated!
If you are building a pond with concrete or a liner – and can therefore choose your own goldfish pond size – then you can work out what volume of water it will hold by following this simple rule:
- Measure the volume of the pond in cubic centimetres by multiplying the length of the sides in cm by the depth in cm.
- Divide this amount by 1,000 to give you the volume in cubic litres.
- Divide this number by 4.5 in order to give you the goldfish pond size in gallons.
Remember that you will not be filling your pond right up to the brim with water, so account for this when doing your calculations!
How many goldfish can I keep in my pond?
It is really important not to overcrowd your goldfish pond, in order to allow your fish room to grow and thrive. An overcrowded pond will not provide a healthy environment for your fish!
The pond size that goldfish need is often debated and there’s no one right answer. To give a reasonable idea of the volume required, many people use the rule of one gallon of water for every inch of fully grown adult fish.
If you stock your pond with small, young goldfish remember that they will need room to grow and develop.
Creating a large enough surface area
As well as considering the overall volume of your pond, ensure that the surface area of the pond is large enough to allow for oxygenation and viewing your fish. The surface of your pond should be the largest “side" of the pond’s shape.
The depth of the pond
When keeping goldfish outdoors, it is vital to make sure that your pond is deep enough to allow your fish respite from the sun and to prevent the water from freezing all the way through in cold weather.
A depth of four feet is ideal, although this is not a firm rule and there is some room for variation in this number. Building a goldfish pond that is very deep may cause problems with the oxygen levels in the deepest parts.