Building a pond as a beautiful addition to your garden is a lot easier if you are well-prepared. Follow this simple step-by-step plan to build your dream pond.
The best time to build a pond is about March or April. That will allow the pond time to develop a biological equilibrium during the growing season. You can also do it in September or October. At that time, you can build the whole pond, but do not fill it with aquatic plants. Do that in the spring.
The next step is to calculate the depth of the pond. Every species of aquatic plant has its own preferences. Therefore, it is important to know the right spot for setting each type of aquatic plant. If you decide to build a pond with different depth levels you will have a greater choice of aquatic plants than for a pond with just one water level.
To keep your pond water clean and clear, you should also consider installing a helophyte filter. This natural filtering system uses certain plants to purify the water.
The first step in building your pond is digging. Bear in mind that you need to dig a hole that is bigger and deeper than the size of the finished pond. You will need a layer of white sand, and possibly also a paved edge, to strengthen the pond floor. To prevent groundwater from entering the pond while it is under construction, it is important to know the depth of the groundwater level. You can usually find this information on the internet. If the groundwater level is normal to high you can pump out the water or dig out the pond at the end of the summer.
If you wish to construct a pond with several depth levels, you should start by digging out the shallowest level. Then dig out each depth level in turn. Don’t spend too much time digging in case the sides fall in.
Cover all horizontal surfaces with white sand. This sand ensures that groundwater or rainwater does not push up through the pond liner, but drains away at the sides. Next, cover the sand with a special protective overlay. This is used in combination with the sand to prevent damage to the pond liner.
Use a pond liner to make the pond watertight. There are several types and thicknesses available. Ask your garden centre or pond specialist for advice about this. You can easily calculate how much pond liner you will need with the following formula:
Push the liner as tightly as possible against the sides and onto the floor. Don’t stretch it too tightly. The liner will be pushed further down and against the sides during filling. Don’t worry if there are some folds in the liner. When the pond is biologically active these folds will make a nice hiding place for little water creatures.
Allow the liner to overlap the edge of the pond by at least 50 cm and finish off the edge of the pond as you wish.
It is preferable to fill your pond with tap water. Groundwater usually makes the water in a pond brown and murky. While you are filling, it is a good idea to keep an eye on the water meter so that you know exactly how much water is in the pond. It is good to know this when you need to use pond maintenance products to improve the water quality.
After filling, you can start testing the water quality of the pond. Pay particular attention to the water hardness (GH level). This level should be about 12 and you can raise it by using a natural pond maintenance product, such as GH Plus. From now on, add beneficial bacteria once a week to maintain a good biological equilibrium. Read more about natural pond maintenance products here.
When you are choosing aquatic plants, you naturally choose the ones that you find pretty, but bear in mind that you want to create a biological equilibrium and that certain plants have a preferred depth. Read through the zoning system carefully for varieties of marginal pond plants, marsh plants, aquatic plants, water lilies, oxygen plants en floating plants.
A helophyte filter is a natural filter system which uses beneficial bacteria to purify the water. A combination of porous materials such as good-quality lava and substrates or gravel can serve as a host to these bacteria. The best purifying plants should be planted in the lava. Allow about 8-10 aquatic plants per square metre. These purifying plants absorb nutrients from the water so that algae are unable to multiply and the water quality remains high. After all your hard work, you can enjoy your new pond and take care of it according to the seasons.