Fish Ponds Guides

Fish Pond Setup – How Much Sunlight Does Your Fish Pond Need?

Fish Pond Setup – How Much Sunlight Does Your Garden Fish Pond Require

The addition of a water feature or pond of some type to a garden, whether rural or urban, has always been a popular component. The calm and tranquility offered by a body of water is beyond question, and a water feature of any type will enhance any garden, large or small. 

Fish Pond Setup - How Much Sunlight Does Your Fish Pond Need

The creation of a garden pond is a wonderful asset. Even a tiny body of water will attract wildlife and create a focal point. In an urban setting, even a small pond setup can provide a vital lifeline to species of frogs and newts and give untold pleasure. 

A garden pond is the perfect way to begin or expand your fish keeping hobby; whether you’re an experienced aquarist wishing to explore new, hardier fish species able to withstand outdoor conditions, or whether you are new to the hobby and introducing added interest to your pond by introducing fish.

When coupled with the stocking of either a single species or a combination of fish species suitable for an outside pond, there is simply no greater pleasure.

A garden fish pond is likely to be a man-made structure – unless you are lucky enough to have a natural pond, but they can still be wonderful additions to the garden providing peace and pleasure.

The addition of beautiful aquatic plants, rocks and decorative structure will create a beautiful focal point and centerpiece for any garden and, of course, the inclusion of appropriate fish species will make a lovely scene.

There will always be a fishpond size suitable for your garden, even if you only have a very small area available. From ready made patio ponds or tubs, or your own creation dug to size and carefully lined with a pond liner, there are many ways to create your garden pond. 

Choosing the Location of Your Garden Pond

Note: Sunlight is important for a garden fish pond. Ponds in permanent shade should be avoided. Partial shade is acceptable, as we’ll explain in more detail as this section of our post progresses, but a sunny spot with adequate protection from excessive harsh sun exposure is ideal.

Choosing the location of your fish pond requires careful consideration, and one of the main elements of this decision will be access to sunlight, which is vital to the general health of your pond environment.

A fish pond with the associated planting and natural foods that will enter an outside pool creates a natural ecosystem in conjunction with your fish species, and the amount of sunlight is an important component within this ecosystem. If you have Koi carp, you can read our guide to Koi pond plants.

The general advice is to create a garden pond in a sunny position; however, shade for a proportion of the day, or an area that is in dappled shade is perfectly fine. Sufficient sunlight for approximately 5 hours daily is generally deemed sufficient for the maintenance of a healthy pond environment.

However, it is difficult to give strict advice on the number of daily hours because conditions will vary enormously from garden to garden according to the individual circumstances. Such variables include:

  • Fencing and other hard material structures
  • Garden planting, including mature shrubs
  • Trees, taking into account their height now and expected height, rate of growth, and whether they are deciduous or evergreen.
  • Aspect of the garden; for example is it south or north facing.
  • Shade patterns – how shade from fencing, shrubs and trees is cast upon your garden as the sun takes its course

It is important to observe your garden over time in respect of these elements, so that you can make informed choices regarding the placement of your garden pond.

An area of the garden that is in constant shade will not thrive well; it will probably become quite stagnant which is unhealthy generally but will also attract mosquito’s which will lay their eggs within the stagnant body of water. That said, some fish such as Guppies appropriate for garden ponds, will be content to eat the mosquito larvae

fish pond setup

Aquatic Plants and Their Need for Sunlight

Aquatic plants, like any plants, need sunlight as an energetic source to photosynthesize and consequently to thrive and grow.

Plants are so important within a pond as they provide oxygen as a by-product of photosynthesis; naturally vital to the health of your fish.

All green plants need sunlight for photosynthesis as they contain chlorophyll and this is what absorbs the sunlight for this complex process. 

Photosynthesis is a chemical process by which green plants convert light energy into chemical energy. Energy from light is the energy source used by green plants to photosynthesize. Photosynthesis takes place in the leaves of a plant and this process requires carbon dioxide and water, and using the energy from the sun the process produces glucose and oxygen, with this by-product of oxygen being so vital to the health of the pond and fish.

So in a nutshell, it is vital to the health of the garden pond that your aquatic plants remain healthy by having sufficient sunlight to facilitate photosynthesis and produce oxygen for the pond.

Aquatic Plants That Thrive In Sunny Positions

Acorus gramineus ‘Variegatus’ 

Pond setup Acorus GramineusThe common name for this plant is the ‘Variegated Sweet Flag’. They love moisture and can be planted in shallow water, either secured within the substrate at the bottom of your pond or within a planting basket. Don’t plant Sweet Flag in deep water though – it loves its feet in water but its leaves in the sunshine!

The good thing about this plant is that it will provide you with additional plants as time goes by – you can divide it as required (usually every two to three years) and replant them. This is not just to increase your plant stock, but is actually necessary for the health of the plant and to prevent them becoming pot bound if planted in a basket.

Sweet Flag is good natured and easy to keep. In Spring just pull out any dead foliage if this is required. It doesn’t attract pests or diseases either, so it is a good low-maintenance option. It has a height and spread of approximately 18 inches, and will reach its final size any time from two to five years of age.

Water Lilies

Pond setup Water LiliesWater Lilies need two things in life! Full sun and still water! So fast flowing rivers are out, but a still garden pond provides the perfect environment.

These are stunning plants – everyone will recognize the water lily, whichever variety you choose. 

With its flat, round, floating leaves, the water lily provides amazing decoration together with cool, shady havens for your fish and any wild pond dwellers that inhabit your garden pond.

Water Lilies are aquatic plants that come in many varieties, and the range and selection is huge. Some have a more delicate growth habit and are great for a small garden pond, whereas others produce large spreading leaves and are best suited to a lake environment.  Be careful when you’re choosing which variety of water lily you need – the leaves of your plants should never cover more than approximately two-thirds of your garden pond; you don’t want complete coverage.

As with Sweet Flag above, you’ll be able to divide your plants at root level once they are fully established after about 3 to 5 years but, again, be careful not to overpopulate your pond and create too much leaf coverage.

Again, in common with the Sweet Flag, little care and maintenance is needed with the Water Lily – simply remove dead and dying leaves in the Fall.

Arrowhead (Sagittaria latifolia)

Pond setup ArrowheadAn interesting aquatic plant with a somewhat tropical appearance, the Arrowhead enjoys life in shallow water. 

As its name suggests, the leaves of this plant are shaped like arrowheads. If provided with the appropriate conditions, the arrowhead plant will form into dense clusters, providing areas of much needed shady refuge in a pond that benefits from a fully sunny position in the garden.

Arrowhead produces little white flowers during the summertime – they aren’t dramatic or stunning but, in conjunction with other aquatic plants, these white flowers make a good show and create added interest.

A note of warning about Water Lettuce – Pistia stratiotes

Often recommended as a sun-loving aquatic plant, we suggest you think carefully before contemplating introducing this species of plant to your garden pond. 

Whilst it is an attractive pond plant, Water Lettuce is non-native to the USA and is a very invasive species of plant. Water Lettuce is capable of completely covering a body of water, forming thick floating carpets of dense plant matter. They can produce a covering so dense that they can cause the depletion of oxygen within the pond which is dangerous to your fish.

Providing Shade for Your Garden Pond

Whilst garden ponds in full shade aren’t to be recommended, it is necessary to create shady areas in ponds that are in full sun.

Full sun is as problematic as total shade for a fish pond. The water temperature will rise to unacceptable levels, having detrimental effects upon your fish stocks. Algae will proliferate in a full-sun pond and, whilst some algae is a great food source for your fish, when it takes over it creates health problems and simply looks unappealing.  

If you have no choice but to locate your pond in full and constant sun, then shade will need to be artificially created. This can be done with general garden planting together with the planting of marginal plants that will create shady havens. Floating aquatic plants that thrive in full-sun will be an excellent choice – water lilies are a good choice for the larger pond, as they will provide good protection for your fish.

Other alternatives are man-made structures or coverings to provide shade. Awnings and sun canopies are good options, as too would be a made-to-measure wooden covering that provides shade to one part of the pond.

Some shade is vital for the health of your fish and the control of algae growth, but excessive shade will restrict your choice of planting and run the risk of stagnation. Plants suitable for various levels of shade are outlined below, and careful selection of plants will keep the water well oxygenated and provide a good habitat for your fish.

Aquatic Plants that will thrive in Partial Shade

Although all green plants need sufficient sunlight to photosynthesize, some need less than others. There are some species of plants that can survive in conditions of lower light – we only have to consider the example of a forest floor where certain plants survive under the shady canopy of large, spreading trees.

If you have a shady garden which has large shrubs and/or trees surrounding it, a suggestion to facilitate the provision of more sunlight to the pond is to prune or coppice these shrubs on the south side of your garden in order to ‘open up’ the area. Alternatively you could remove the trees altogether, but this may feel too dramatic.

Coppicing (as well as pollarding) is a method of pruning various trees by cutting multiple stems all the way back to ground level, which can keep them more shrub-like, allowing increased levels of sunlight to penetrate.

What do we mean by Partial Shade?

Plants do not need to be in full sunlight all day long to be able to photosynthesize and create oxygen for the pond and remain healthy. 

In fact, plants are categorized into those needing full sun, partial sun, partial shade and full shade. These categories for the requirements of sunlight are as follows:

  • Full sun – these plants require a minimum of 6-8 hours of direct sunlight daily
  • Partial sun – these plants require 3-6 hours of direct sunlight daily
  • Partial shade – these plants also require 3-6 hours sunlight daily as with partial sun, but they need protection from the afternoon sun
  • Full shade – these plants require as little as 2 hours of direct sunlight daily

So plants that are recommended for growing in partial shade or even full shade will manage to survive healthily and produce sufficient oxygen with only approximately two to fours hours of direct sunlight each day.

Shade Tolerant Aquatic Plants Suitable for Shade or Partial Shade

Planting an array of shade tolerant plants in your garden pond will produce and maintain good oxygen balance and general health of the pond. We’ve compiled a list below of shade tolerant plants that will enhance the appearance and health benefits of an outside pond situated in a shady spot.

Water Forget-Me-Not (Myosotis scorpioides)

Water forget me not

Water Forget-Me-Nots by Theo Crazzolara (Flickr)

This hardy plant enjoys dappled shade. It can be grown in aquatic compost which is 10cm deep ideally. It works equally well in natural ponds and man-made ponds alike. 

With a man-made pond that you have created yourself, you can plant the Water Forget-Me-Not at the water’s edge to create a lovely soft, natural appearance to the pond and to hide the edge of the pond liner. It can also be planted in shallow water. Plant directly into some aquatic compost.

Apart from dappled shade, this plant enjoys a south facing or west facing position.

This plant will slowly and steadily grow and expand in size but is not an invasive species. You can divide it every two to three years to create new plants for your pond.

Isolepis (Scirpus) cernuus

Pond setup Isolepis (Scirpus) cernuusWith each stem tipped with tiny silvery-white flowers, this petite and delicate rush plant will enjoy a position within your pond which provides soil that is submerged by approximately 5 centimeters of water and therefore is permanently wet. It doesn’t thrive as well in very deep water.

Plant in aquatic compost and finish off with pea gravel to secure the compost.

The lovely white flower heads look like little tips of light, so is sometimes known as the fiber optic plant.

Marsh Marigold (Caltha palustris)

Marsh Marigold Pond SetupIn the wild, this plant tends to grow in the shallow water at the margins of ponds or close to streams. 

In spring and summer it produces large and shiny yellow flowers, which creates a beautiful display. The Marsh Marigold will grow to a height of approximately 8 inches, and is easy to grow and maintain.

Grow in dappled shade and plant in shallow water at the margin of the pond, either directly into aquatic compost or in a planting basket.

Water Hawthorn (Aponogeton distachyos) 

water hawthorn

Water Hawthorn in the foreground and Water Lilies in the background by cultivar413 (flickr)

Water Hawthorn (Aponogeton distachyos) provides an excellent alternative to the Water Lily which is more invasive and can take over a garden pond. 

As per the Water Lily, Water Hawthorn is an excellent aquatic plant for deep water. The enlongated, green leaves float on the surface of the water (in common with the Water Lily). The young leaves are really lovely, often speckled with a maroon color.

This Water Hawthawn produces white flowers that reveal themselves just above the water line, and they have a distinctive scent that many have likened to vanilla.

This is a very hardy aquatic plant species. If you live in an area with mild winters it will survive and flower all the way through the winter from fall until the following  spring. If you live in an area with icy winter weather, it will die back during this spell.

Unlike Water Lilies, this Water Hawthorn grows really well in shady conditions although, as you may expect you will get a greater floral display if planted in partial shade. Full, harsh summer sun will not be tolerated by this plant, so it’s definitely a wonderful choice for ponds located in shady conditions.

Good Oxygenating Plants that will Tolerate Shady Conditions

Anacharis

Anacharis ElodeaAnacharis is sometimes known as Brazilian Waterweed and is an excellent, easy-to-keep plant for all pond types. With fern-like bright green leaves, this aquatic plant will help to oxygenate your pond water, and will clear and clarify the water and reduce the growth of algae.

This plant will happily anchor its roots into the gravel or sand substrate at the bottom of the pond, or it can just as happily float free.

It provides good hiding places and coverage for fish, and many fish types will choose this plant in which to spawn. Many fish enjoy nibbling on this plant species, but this can be viewed both positively and negatively – on the positive side it provides a natural food source for you fish during any weekends away. 

Plant either directly into the substrate or in small pots placed strategically at the bottom of the pond.

Hornwort (Ceratophyllum demersum)

Hornwort fish pondThis is a perennial plant with forked green leaves and very small flowers that appear in summer.

Hornwort likes to remain submerged within the pond and, although it is happy enough in full sun, it enjoys full or partial shade. Although it will die back if you live in  an area with harsh winters, you will probably get new growth in spring from buds that survive over the course of the winter in any mud collecting at the bottom of your pond.

There is no need to plant this in a basket or within compost or substrate – it enjoys to float freely within the pond. 

Shade from Trees – Good or Bad News for Pond Owners?

Trees are a wonderful asset to a garden, both aesthetically and in terms of biodiversity within our gardens. They provide us with degrees of shade, from full to dappled depending on the tree variety.

When considering where to locate your garden pond, think carefully if you have existing mature trees in your garden. Take the time to track the shade created by your trees and/or large shrubs as the sun moves round during the course of the day. If your trees provide partial shade for some of the day, that would be ideal; however, if the trees create dense and impenetrable shade, this will lead to stagnation and problems with both your fish and aquatic plants.

Additionally, assess the falling leaves and other debris that your trees create, particularly in Fall if they are deciduous trees that shed their leaves.

Leaf detritus can build up excessively in garden ponds but, of course, this can be cleared out periodically – it is a question of degree. Leaf matter can clog the filters preventing them effectively working, which can upset the balance of your pond.

You can, of course, put a mesh covering over the pond to catch falling leaves and debris, but this will prevent wildlife using the pond.

Give a thought also to the growth habit and final size of your trees. As they grow year on year, the tree roots can become bigger and more invasive, and could potentially physically disrupt your pond. 

Some research into your tree species, together with the observation of the shade created and leaf debris, as mentioned above, will give you the information you need to make appropriate decisions regarding the location of your pond.

Conclusion

Whether you’re an experienced fish pond owner or are looking to expand your hobby from an indoor aquarium to an outside pond, the addition of a pond will really enhance your garden.

A pond is a wonderful asset in a garden. Even a tiny body of water will attract wildlife and create a focal point. In an urban setting, small ponds can provide a vital lifeline to species of pond frogs and newts and give untold pleasure. So you’ll be doing your part to help the environment as well as engaging in your hobby. 

When contemplating the location of your fishpond, take time to consider your garden and its aspect. How much sunlight does it get? Are there any areas that are in persistent shade or constant sunlight? Do you have any deciduous trees that will drop their leaves in the Fall creating problems of debris within your pond?

Observations of this type will help you identify the best possible location of your garden pond. 

Remember, too, the importance of aquatic planting, both within the pond itself and in the margins, to create both shade and safe havens for your fish. Use our guide above to help you in your selection of plants for both the sunny and the shady locations.

There are obviously both pros and cons for different light conditions, and varying plants for each set of conditions. However, a good rule of thumb is to choose a spot that will provide sunlight for an average of four to six hours per day. This will give you a wide range of plants to choose from, allow algae to thrive but not proliferate and take over, and allow a healthy balance to be established and maintained within your pond, avoiding problems of stagnation.

About the author

Authority Aquarium Staff

Authority Aquarium Staff writers are experts and aquarium enthusiasts, our in-house marine biologist fact checks all our content and reviews to bring you the best advice for your aquarium health.

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