Often times most fish farmers ask “ must I cover a concrete fish tank with something to provide shades on my fish farm? Well, erecting a structure to provide shade for the fish is not necessary because the pond has a way of protecting the fish against the effect of the direct sunlight.
After feeding the fish for a day or two, the water in the pond turns green and this usually serves to protect the fish from access to direct sunlight when next you have the privilege of entering a fish pond either earthen pond or concrete pond, you will discover that the water is always cold. Therefore to me, erecting a shade is indeed an extra cost on pond construction
Meanwhile, many new pond owners are concerned about the effects of sunlight for pond fish. This is an important issue, and the solution will depend on various factors.
Sunlight can be beneficial to your fish, but it can also harm them, and the outcome largely depends on the pond’s construction, location and how it is maintained.
How Sunlight Impacts Pond Fish
When a pond is directly exposed to sunlight without shade the temperature of the water will increase. This increase in temperature will lower the amount of oxygen which is accessible to the fish, while also promoting the growth of algae. Fish which are exposed to excessive sunlight may also receive sunburn.
Each pond is unique in the manner in which it will respond to the sun, and while ponds which are big and deep may not have much of an issue, the smaller ponds which are typically found in backyards may be adversely impacted.
Algae enjoy sunlight and will thrive when exposed to it. If your pond contains koi they should be exposed to no more than a few hours of sunlight per day. Anything more than this could be problematic for them. The typical pond will receive between four and six hours of sunlight per day.
Sun is the most important renewable energy source nature has given to our world. As a matter of fact, sunlight and heat provide vital energy that sustain live on Earth. Without sun, no life will exist on the planet Earth.
The benefits of the sun are numerous. Both plants and animals benefit immensely from this special gift of nature. As a catfish farmer, I will like to expose other farmers like me to certain things we enjoy from sunshine without notice. Of a truth, your catfish farming business could be affected by the intensity of sunshine.
6 Importance of Sunshine for Your Ponds
1) It Acts as Water Color Stabilizer: Color of pond water can change from light green to grey or blackish due to many factors such as overstocking, excessive feeding and poor lightning from the sun. It has been observed that pond water changes color during a period of little or no sunshine.
Even when there is no case of overfeeding/stocking, water still changes color during season of little sunshine especially in pond system. This establishes the fact that heat and light from sun help in stability of pond water.
2) It Enhances the Growth of Water Plants: Growth of plants is made possible and sustained in pond water through sunlight. Energy tapped by plants through photosynthesis is stored in calories. These calories are used up by fishes that feed on them.
Water plants absorb ammonia from the pond to keep pond water habitable for catfish production. By this process, water quality is regulated. Apart from water plants, other plants that are used as inputs in catfish feed depend solely on sun as a source of energy.
3) It Regulates Water Temperature: Tropical catfish perform well in slightly warm water. The heat from sun helps in regulating pond water temperature through direct and indirect means. When the temperature is too low, the ability of catfish to regulate its body temperature will be affected. Evaporation process through heating from sunshine results in rain and cooling of the pond environment.
Rain helps in refreshing and replenishing ground water that supplies catfish ponds. However, to avoid the negative impact of sun heat on the pond, pond water must not be too shallow. Pond water level of between 3-4 feet is recommended except in other system apart from pond system.
4) It Helps Catfish Metabolic Activities: Catfish eats little in the time of low temperature in the tropic. In a situation of low temperature, digestive system of catfish slows down. The growth is less obvious. The length of culturing season becomes longer. Also profit margin reduces.
5) It Supplies Vitamin-D: Sun ray is rich in vitamin D. There is a possibility that catfish can tap this vitamin through their skin like man. From literature, vitamin D from sun is important for bone formation and also helps in absorption of calcium in feed.
6) Ultraviolent Ray from sun helps in water sanitization by killing some water pathogen and leaving some less harmful ones. Pathogen-causing diseases are kept at check by the help of this ray from the sun.
How To Control Your Pond’s Sunlight Exposure
The best way to manage your pond’s exposure to sunlight is by adding shade. Terrestrial shade can be created by adding marginal plants or trees near the side of your pond.
However, during fall leaves will fall from the tree and will cause serious problems if they are allowed to accumulate in the water, so you will need to perform netting or clean them out. Dwarf Cattail which is planted on the west or south side of the pond will provide excellent shade for the fish.
Aquatic plants can also be used to manage sunlight, and some of the best include water hyacinth or water lilies, which create shade beneath the water that can be used by your fish. The lilies can be planted via plant bags and or baskets and situated in advantageous locations throughout the pond.
An alternative to the planting of trees could be a canopy or manmade structure which will cast shade over the pond. The right canopy can also add style to the area.
Perhaps the easiest solution is fish shelters or caves. The shelters can be placed in the water and will allow the fish to swim beneath or within to get shade whenever they need it, while caves will also perform the same function, although constructing them may be more complex. In addition to protection from sunlight, these structures will also protect your fish from predators.
Never Over Shade The Pond Too
Just as too much sunlight is bad for fish, too much shade is equally so. The most ideal ponds are those which have some areas reserved for sunlight, while others which are reserved for shade. This will give the pond a balanced temperature which will make your fish healthy and happy.
Now let us have a look at the benefits of shading your fiah ponds below:
Benefits of Shading a Pond
1) Slows Algae Growth
Algae grow the fastest during the hottest months when sunlight is the most intense, and if left unchecked, they can quickly take over a garden pond. Ponds in the shade may still have issues with algae, as they can grow with minimal light, but providing shade will help slow down growth making it more manageable.
A partially shaded pond will have much slower algae growth in comparison to a pond constantly exposed to sunlight. Too much algae can become a huge problem for a pond, especially one with koi or goldfish. As algae die off and more start to grow, massive amounts of oxygen are removed from the water by decomposing beneficial bacteria.
During periods of algae blooms this process can reduce oxygen content in the water to dangerously low levels, putting huge stress on fish.
Shade will certainly help slow algae from growing, but if you’re already experiencing a rapid bloom, a more direct approach may be needed to get things under control first.
2) Improves Oxygen Levels
High temperatures reduce the oxygen holding capacity of water, meaning ponds will be holding less oxygen during the warmest summer months. Fish also become more active during summer, eating more as their metabolic rates increase.
This increase in activity means the fish produce more waste, and beneficial bacteria will need to work harder to break down the excess. These bacteria require oxygen to function, just like fish, and may struggle to carry out their job as oxygen content decreases.
Shading a pond from sunlight will help lower the overall temperature and improve the capacity at which water holds oxygen. Algae also grow the fastest during the day, so slowing their growth by blocking sunlight will help improve oxygen for both fish and beneficial bacteria.
3) Makes Fish More Comfortable!
Both goldfish and koi prefer a pond within a specific temperature range, generally between 65 and 75 F degrees. They can certainly survive in much colder or hotter water, but that doesn’t mean it’s ideal for them. Warmer water temperature, along with pH, also has a direct effect on the toxicity of ammonia.
This waste substance is very dangerous to fish, but the majority is safely removed by the beneficial bacteria living in your pond and filter box. Problems may occur during summer where fish produce more waste (ammonia) and temperatures are also high, which causes the ammonia to become more potent.
Shade is just one thing that can help with this issue by allowing water more time to cool down from the sun, and giving bacteria more time to breakdown substances before they can build.
In much smaller ponds, such as preformed ponds, fish can literally boil to death if the water is exposed to constant sunlight throughout the day. Smaller ponds act as insulators, taking in heat and retaining it much more readily than a larger body of water.
Even with aeration, shallow water may not be able to cool down fast enough, so providing shade is essential if you want to keep your fish healthy and happy in a small environment.
Methods to Provide Pond Shade (Top Methods)
Option 1: Pond Plants (Real or artificial)
Shade Amount: Partial Shade
A great natural way to provide shade to pond water is to add pond plants! Both real or artificial plants will be able to provide shade, but only real pond plants will be able to give your water more oxygenation and help with natural filtration.
The best plants for shading water and providing shelter to fish would be water lilies or lotus, as their foliage grows across the water, blocking a large chunk of UV light. Most floating plants would be ideal for adding shade to a pond, and luckily these come in both real and artificial varieties.
If you just want some shade and shelter for your fish during summer, artificial floating plants will provide those benefits without requiring any hands-on maintenance. If you decide to go with real floating plants, it may take some time for them to grow and become established, but the results are fantastic in the long run!
As well as floating plants, marginal plants can also provide partial shade to a pond, creating areas where the water is cooler and less UV light penetrates. These kind of plants are usually added to the sides of a pond, fleshing out the embankments.
A few can grow very tall with lush green foliage, and these provide the best shade to pond water. It’s less common for these kind of plants to have an artificial alternative, so if you don’t want to care for real plants, we recommend sticking with artificial floating types for best results.
On top of shading a pond and helping cool down the water, both types of pond plants also create “safe spaces” for your fish to hide when stressed or threatened. Plants provide a natural form of shelter which fish love to hang out around when they need to relax for a few hours away from the sun and everything else.
Option 2: Shade Sails
Shade Amount: Partial-Full Shade
Unlike pond plants which only provide partial shade to the water, shade sails can provide up to full pond shade, and can be altered to suit your needs. These covers are generally made from durable UV resistant fabric, often polyproplyene, and work to block a large amount of UV light from penetrating into pond water.
They’re fixed above ground and can be positioned to provide full shade or partial shade to a specific area of water, with most models blocking up to 90% of all UV light.
If you have particularly hot summers and a small fish pond, investing in a high quality shade sail is probably the single best method of cooling and shading your water. There is no maintenance required when installed, and due to the amount of UV light the material can block, it can reduce water temperature by a large amount daily.
They will also work fine in larger ponds, allowing you to section off a shaded area of pond water for your fish to hide, and giving water a chance to cool as it circulates. They will also help reduce algae growth and deter airborne predators, such as herons, from taking pond fish.
A downside is they’re very noticeable and not something you can easily hide. Shade sails will also block sunlight from reaching regular pond plants, so you would need to make sure your plants can grow in partial shade or position the material so the sunlight still hits the plants.
Other than this, however, shade sails are probably the best method of shading AND cooling pond water during summer, and we’d recommend them to anyone who has a fish in a full sun exposed pond.
Option 3: Pond Water Dyes
Shade Amount: Partial Shade
The best pond dyes are made from non-toxic food-grade ingredients, which are the same dyes used to color food we consume on a daily basis. They come in a range of colors, with blue, turquoise, and black being the most popular and functional for blocking sunlight.
Blue dyes are a good all-round colour which will provide a more natural pond aesthetic and help block a large chunk of sunlight reaching through your water. They look great for most types of ponds, and we would recommend blue as a good starting choice for first time dye users.
If you want maximum algae control and UV reduction, black dyes provide a much higher reflective surface and a darker water color. This color will absorb more UV light and reflect more light off the pond water as the dye becomes established, but the color is less natural in comparison to blue.
Pond dyes are safe for both fish and wildlife, and usually provide around 2-3 months of color before needing a top up. They will also help hide your fish from predators, as the dyes will make it much harder for flying animals, such as herons, to see your fish while overhead.
Pond dyes won’t provide as much direct shade as plants or shade sails, but can be used alongside these options to help further control algae and reduce water temperature from UV light exposure.
Option 4: Fish Shelters
Shade Amount: Partial-full Shade…for fish!
Although they may not be suitable for small ponds with shallow water, they work great for ponds with at least 3ft+ of water depth. If you have pond plants which require plenty of sunlight and you don’t like the idea of a shade sail, a shelter should provide your fish enough UV protection to cool down when needed.
If you have lots of fish, or larger koi, you can add multiple shelters in different areas of the pond for more places to hide in summer. As well as providing shade, they work great to stop herons taking fish, so would be a good addition to any koi or goldfish pond.
The choice of design is mostly down to personal preference, with both plastic and mesh working well to shade a fish pond. If we had to choose, we’d probably select a mesh shelter as they are softer (less chance of injury), easier to sink, and still provide good UV coverage.
Here are some amazing fish farming books to guide you further and help you get started: