Guide written by:
Jeremy, Construction site supervisor, Cardiff
In nature, plants and animals coexist in perfect balance. The primary challenge in developing a pond is to reconstitute that same viable ecosystem. Choosing the different plants and/or species of fish wisely is crucial. Depending on the elements you select, different bacteria or insects will move in, helping to maintain the ecosystem.
The quality of the pond's water is the result of a properly configured filtration system. This piece of the puzzle is just as important as all the others because no matter what the species of plants, they will require clear, oxygenated water. A fountain or water jet can also provide the necessary oxygenation, all the while being aesthetically pleasing.
Oxygenation is the technical term for how much oxygen (O
2) the water contains. The water should have between 8 and 12 mg/l (milligrams per liter). Within this range, plants and fish will be able to live and develop without any issue. In order to attain and maintain a minimum oxygen level, one needs to create an exchange of gases, either intermittently or continuously, between the pond water and the outside atmosphere. What does this have to do with decorations, you ask? The answer is simple, as this exchange of gases can be manifested in different ways: water jets, fountains, waterfalls or streams, among other elements.
A pump or any filtration system that is equipped with a specific outlet, will suck up the water from the bottom of the pond and expel it through either a nozzle (for a water jet or a fountain), or a dedicated structure (for a waterfall or stream) in order to add oxygen to it. It is up to you to select the most fitting ornaments and decorations for your pool. It's important to remember that as soon as the pond water drops below 10° C, the pump system must be shut down.
Your garden pond's decor, banks, bottom and fish shelters can be composed of of gravel, stones or rocks. Gravel is ideal for the bottom of the pond; with the average pebbel size ranging from 10 to 40 mm, it creates a surface that is highly conducive to the proliferation of aquatic insects. These insects are useful for maintaining the pond's ecosystem in balance by feeding on micro-organisms, resulting in the degradation of a part of the contained organic matter. Gravel is also fertile ground for aquatic plants to get a solid hold.
All around the pond, on its edges, or mixed in at the bottom with the gravel, medium-sized stones are perfectly adapted for these surroundings and will further facilitate the anchoring of plants. Available in different colors, these accessories can easily create a harmonious atmosphere. Rocks, last but not least, are adapted to multiple roles. Apart from adding a touch of naturalism to the installation (used in a waterfall, stream, etc.), they can also conceal a filtration system or make excellent fish shelters.
Along with stones, plants are the primary elements that really give a natural touch to your garden pond. They are countless options, with many sizes, shapes and colors. The plants you end up selecting will essentially depend on the depth of the water in which you want to put them (hence the importance of having several levels in your pond). In addition to the lush, green visual aspect, plants are also natural filtration systems and they contribute to the oxygenation of water, while absorbing many harmful or toxic compounds. It is however necessary to classify the plants in two different categories: plants on banks and aquatic plants.
Having plants on pond's banks will allow for a vegetal transition from land to pond. There are a vast amount of choices in terms of what plants you can choose. The plants will also stabilize the banks with their roots, limiting the chance of landslides and strengthening the pond's hold in the ground. Perennial plant species are often used, the most common of which are forget-me-nots, hostas, lilies, daylilies. Some plants are to be absolutely avoided in all cases: knotweeds, any type of willow or any other invasive plants.
The type of acquatic plant you use will depend on the depth of the water. Anything deeper than 50 cm will offer a lot more types and species, as entire families of water lilies or surface cover plants become accessible. However, be careful not to go overboard on the surface cover plants if your pond houses any fish. As a general rule, acquatic plants can be placed down to a maximum depth of 1 m.
The most common fish to introduce into a pond are koicarps (Chinese carps), which are very colorful (yellow, orange, red, white...). In addition to being living, breathing works of arts, they will also an extra splash of color to the pond.
The majority of white fish (tench, barbel, roach, nase, etc.) are more tolerant of variations in water quality and temperatures.
Of a more delicate disposition, but no less interesting, salmonids (trout, brook salmon, char, etc.) are also a valid possibility. Keep in mind that they are however very demanding in terms of oxygen (water must contain a minimum of 10 mg/l) and they are incompatible with some plants (such as water lilies).
A garden pond can liven up any garden! With so many options available, here are some pond-related accessories, advice from our editors and more helpful guides:
Guide written by:
Jeremy, Construction site supervisor, Cardiff, 159 guides
Electrician by trade, I first worked in industrial estates where I installed, wired and fixed a large number of electrical installations. After this, I managed a team of electricians for this type of work. 10 years or so ago, I turned to building and construction. From the modest family home, to gyms and theatres, I have been able to coordinate, audit and organise all sorts of construction sites. For 4 years now, I am restoring and building an extension to a bungalow in the heart of the Welsh countryside. My experience in manual work and my knowledge means I am proud to be of service. Terraces, interior design, roofing, plumbing, electrics, anything goes! My wife, daughter and I, built almost everything we have from scratch! So to answer all of your questions and advise you on choosing your tools? Easy!