FAQ – Building a Pond

Can I use Builders Plastic?

No, Builders Plastic is not UV Stabilised and will break down fairly quickly, and is more susceptible to punctures. Some types of Builders Plastic can harm aquatic life.

Do I need Permission to build a pond?

Generally you do not need permission to build a pond. It may be helpful to get in contact with your local council as some areas may have a limit to the depth that the pond can be made.

How deep does a pond need to be?

This depends largely on the type of fish you want to keep. We would suggest an absolute minimum of 30cm. You don’t want the pond to be too shallow as shallow water can heat up quickly which encourages algae growth. Shallow water also gives predators easier access to your fish.

If you’re planning on keeping Goldfish a minimum depth would be 30cm, if you can go deeper the better. For Koi, ideally at least 50cm – the deeper the better.

What do I need to consider before building a pond?

There are a number of factors to consider when building a pond, these include:

• Size– This is going to be personal preference. You may want something small to attract frogs or birds to your garden, or you may want something large to keep koi. Having a large pond is advantageous as they are easier to stabilise and maintain, whereas a small pond can heat up and lead to algae issues (which isn’t to say you won’t get algae issues in a large pond, this will really depend on a number of factors). The size of your pond may also depend on your local council as there may be restrictions in place.
• Location– You need to consider what you want in your pond. For example, if you want to keep water lilies you will need to place your pond in an area where it will get at least four hours of sun a day. We recommend to avoid placing ponds under trees which will shed a lot of leaves as this may cause frustration down the track. The breakdown of leaf litter can cause algae blooms and can be harmful to aquatic life. Ponds can be situated near garden plants if you are trying to attract wildlife but make sure that the plants are not poisonous or toxic to fish. You will also want to make sure any nearby plant life does not have intrusive roots that may puncture pond liner. The use of underlay can help in this instance.
• Power Supply– Solar powered pumps are an option but they are more expensive to buy and will limit your options. They are only suitable for smaller ponds or water features and are not recommended for ponds with koi or high fish stock. If you can get power to your pond you will have a lot more options. 
• Noise– Having a massive waterfall running can be quite peaceful but when you are trying to sleep it can be quite irritating for you or your neighbours.

How much liner would I need for my pond?

Liner Length = Pond Length + Depth + Depth + 60cm (This allows for 30cm overlap each side)

Liner Width = Pond Width + Depth + Depth + 60cm (This allows for 30cm overlap each side)

Example:

3m (Length) + 0.3m (Depth) + 0.3m (Depth) + 0.6m = 4.2m

2m (width) + 0.3m (Depth) + 0.3m (Depth) + 0.6m = 3.2m

We can then work out the nearest roll size available, and we can cut in half-metre increments.

Should I put Gravel / Rocks on the bottom?

There a pros and cons to having gravel on the bottom of a pond. We normally leave it up to you as what you like appearance wise. Pros and cons are as follows:

Pros:

• Hides the Liner and can give a more natural look.
• Creates an environment for the beneficial bacteria to colonise. This bacteria aids in the breakdown of organic material and toxic compounds, such as ammonia and nitrite, in the pond.
• Gravel may provide you with a media to grow your plants in, although you would need a thick layer.

Cons:

• A lot of material tends to build up in between the gravel / rocks. If this build-up gets quite thick it can be a hard job to remove. Without Gravel / Rocks on the bottom it is a lot easier to clean with a net or pond vacuum.
• The Gravel / Rocks will eventually get a build-up of algae so they won’t stay the same colour they originally were. Algae can be very hard to remove from the gravel. Even though there are treatments to kill the algae, the treatment will generally only kill the filamentous algae and not the colouration they leave on the gravel.
• Aquatic Plants (If planted in the bottom of the pond with gravel) can be quite prolific and hard to maintain. We find it easier to maintain plants in pots.

Can I join Liner?

Yes, there are products available to join liner. We do not recommend to join two pieces of cut liner to make the right size pond with least amount of waste. Doing this creates a weak point in the liner and can be very costly in the long run if not done correctly. The easiest and safest way is to line the pond in one piece.