Learning how to build a fish pond is more complicated than just digging a pit and filling it up with water.
But once you have a pond it is wonderful feature and a great aesthetic addition to your yard.
And it can be rewarding to see your fish thrive!
Like all living creatures, fish require very specific conditions to thrive. To create this conducive environment, you will have to pay close attention to some crucial factors when designing your fish pond.
This article will guide you on how you can build a beautiful fish pond in your garden, and whatever needs to be taken into consideration.
Types Of Ponds
Garden fish ponds are classified into two categories: sunken fish ponds and raised fish ponds.
These are the most common types of fish ponds. As their name suggests, sunken ponds are constructed below the ground level. You will therefore have to dig a pit in the ground when creating such a pond.
So what is the magic formula?
The advantage of sunken ponds is that they easily blend with any surrounding leading to a more natural look. However, constructing a sunken pond is very labor-intensive as there is a lot digging involved. Such ponds are also vulnerable to pollution from surface runoff whenever it rains.
Raise ponds are constructed above the ground. A structure has to be built to hold the water. Such structures are mostly built using concrete or wood.
The secret is:
Raised ponds are easier to build compared to sunken ponds. They are also not vulnerable to surface runoff when it rains.
On top of that, the raised profile of such ponds reduces the risk of a young child falling in. This makes them a safer alternative for people with small children.
The main disadvantage of raised ponds is that look very artificial owing to the fact that they are designed to conspicuously stick out of the ground. They are also more expensive to construct compared to sunken ponds.
This article will outline the steps involved in the construction of a simple sunken pond, you can also view the video below which may help.
Selecting A Suitable Area – What Do You Need To Consider?
When choosing an ideal location for your fish pond, the following factors have to be taken into consideration:
1 – Access To Sunlight
Fish don’t really need sunlight to survive. Nevertheless, sunlight promotes the growth of algae which fish feed on. Furthermore, if you plan on having aquatic plants in your pond, they will need sunlight to grow.
The amount of sunlight reaching the pond will however need to be limited to about four hours of direct exposure per day. Too much sunlight will do more harm than good.
It is simple:
As the water temperature rises, the oxygen concentration in the water will drop and fish may suffocate. Excess sunlight can also cause uncontrollable growth of algae in the pond.
Since your fish pond will only need about four hours of direct sunlight, it should be under some sort of shade for most parts of the day. This could be close to a tree or any other horizontal structure such as a fence.
2 – Maintenance
Surface runoff caused by rain will deposit dirt and other harmful substances into your fish pond. This will lead to constant clogging in the plumbing lines and pollution of the pond.
To avoid having to endure this inconvenience, you should first inspect the area where you want to construct the pond and pick a spot that is slightly raised. This will reduce the amount of surface runoff getting into the pond, making it easier to maintain.
On top of that:
The water level in the pond is bound to drop over time due to evaporation. You will therefore have to replenish the pond from time to time by topping it up with fresh water. It is therefore advisable to construct your pond close to a water outlet.
3 – Aesthetic Appeal
A fish pond can enhance the beauty of any landscape. When designing one, you should ideally choose a location where it will blend with the surrounding.
You should also consider building it where it will be visible from your favorite spot in the house.
Choosing The Size Of The Pond
Most garden ponds cover an area of between 50 to 150 square feet. The ideal size for you will depend on how much space you have in your garden, your personal preferences and how many fish you wish to keep.
However, the pond’s depth has to be carefully considered based on the following factors:
1. The Type Of Fish You Want To Keep
Tiny fish species like goldfish can be kept in shallow ponds that have a depth of around 18 to 30 inches.
Larger fish species such as Tilapia and Koi require more space and an ideal pond for them should have a depth of 40 to 60 inches.
2. The Climatic Conditions In Your Area
Fish ponds constructed in areas that experience harsh winters have to have a depth of at least 40 inches, regardless of the fish species being kept. This will ensure that the fish have enough room to swim even when the surface of the pond freezes.
Similarly, fish ponds constructed in areas that experience hot summers should also be at least 30 inches deep to keep the fish comfortable.
3. The Space Available In Your Garden Or Backyard
A fish pond should be constructed in such a way that it blends naturally with the surroundings. It should therefore not take up too much space in your backyard.
Leaving enough room around the pond will also make it easier to maintain.
Types Of Fish For Your Pond
There are several species of fish suitable for backyard ponds. The ones you go for will depend on whether you are raising the fish for food or ornamental purposes.
You can even combine different species in the same pond. You will have to do some research first before trying this to avoid disaster.
Here are a few fish species that you can keep in your garden pond.
Tilapia is among the most delicious fish species in the world. These fish also mature very fast. They are however only suitable for areas with warm climates, where the temperature ranges between 25 to 30 degrees celsius.
These fish come in several colors including yellow, black, blue and white. A pond full of Koi is a beautiful sight and they can add life to any dull backyard or garden.
Koi are also very hardy and can endure both hot and freezing climates without any problem.
Goldfish are among the most popular species for aquariums and outdoor ponds. They are small, colorful and lively which makes them perfect for ornamental purposes.
And you know what:
Despite their small size, goldfish tend to be surprisingly hardy and some varieties can comfortably live through even the harsh winter cold.
Constructing The Pond – What You Will Need
You will need:
A tape measure – To measure the depth and horizontal dimensions of the pit.
A shovel for digging up soil.
A pick mattock – This can be used to break up rocky or firmly compacted soil.
A can of spray paint or a garden hose to map out the area to be dug.
A spirit level indicator
A hand trowel
Pond lining material – This will be used to line the pit to ensure that water does not sip into the soil. There are two types of pond lining: Rubber (EPDM) and plastic. Plastic lining is cheaper than rubber lining. It is however less durable and harder to work with due to its stiffness.
A pond skimmer – A skimmer will filter out large debris like leaves and small branches that fall into the pond. Such debris can clog the water pump or cause water pollution when they decay.
A submersible water pump – To ensure a continuous flow of water through the skimmer to the waterfall or fountain. This steady circulation will prevent uncontrolled growth of algae in the pond while also keeping the water aerated.
Underlayment – This is placed at the bottom of the pit to protect the pond liner from getting punctured by rocks or exposed roots. Heavy duty underlay material can be bought at a gardening supplies store.
Flexible tubing – This will be used to connect the water pump to the pond skimmer.
De-chlorinator – This is necessary if you intend to use domestic water supply to fill the pond. A de-chlorinator will remove all traces of chlorine which can harm some vital biological organisms in the pond.
Step One – Digging The Pit
After you have identified a perfect location for this project, you will need to mark out the boundaries for the fish pond on the ground.
These markings will guide you while you dig the pit. You can use spray paint or a garden hose to spray some water on the ground along the planned boundary.
Now this is important:
You need to find a place where you can dump the soil you dig up. This soil should not be left near the fish pond because it might end up being washed back into the fish pond.
Digging the pit is the most time-consuming and labor-intensive part of this whole process, but nothing good ever comes easy. Have patience and don’t push yourself too hard. You could get someone to help you through this part if you are constructing a large pond.
The best thing is:
To start digging from the center working your way towards the edges of the boundary lines you have marked on the ground.
It is advisable to gradually dig the pit in stages, digging to a depth of about one foot all the way round before proceeding to two-feet deep and so forth, until you reach the desired depth.
If you’d like to grow some aquatic plants inside your pond, mark out a smaller replica of the boundary inside the pit once you get to a depth of one foot.
This requires that:
The borders of this second boundary should be at a distance of about one foot from the borders of the first boundary line. The space created between these two boundaries will indicate where the shelf for your plants will be.
You can then dig out the rest of the pit along the second boundary line. This will leave a shallow ledge around the pit where the aquatic plants will be placed.
Digging with a large tool such as a mattock or a shovel is bound to leave rough edges around the wall of the pit. To smooth these edges, you can use a hand trowel to scrape off any lumps of soil sticking.
You can use some of the soil you have dug out to fill any holes on the bottom surface of the pit. The bottom surface of the pit needs to be as flat as possible.
The spirit-level indicator will come in handy at this stage in helping you to spot and correct any bumpy patches.
Step Two – Lining The Pit
Now that you have dug the pit and ensured that the bottom surface is level, it’s time to place the pond lining material.
And how do you do that?
First off, you will need to place the underlayment material on the bottom surface of the pit. This will protect the lining material from tiny pieces of rock or lumps of soil which could puncture it. You can then proceed to lay the lining material inside the pit.
Regardless of whether you are using rubber or plastic lining, you will need to be careful not to drag it on the surface too much while you lay it as you can easily damage it. It is also advisable to take off your shoes before getting into the pit to position the lining material.
If your pit has a shelf for aquatic plants, ensure that the lining is positioned to be in contact with the contours of this shelf.
As you do this, try to flatten any visible creases within the lining. It is impossible to eliminate all creases and folds, but try to do away with as many as you can.
The rest will be leveled out by water pressure when the pit gets filled. The lining material should be larger than the pit, so some of it will overlap over the edge of the pit.
Step Three – Filling The Pond
Once the liner has been positioned, the pit can be filled with water. Connect the garden hose to a water outlet and use it to fill water into the pit until it is full. The pressure from the water will adjust the lining to the perfect position.
You can then place the concrete bricks around the edge of the pit to secure the overlapping part of the liner, making sure you cover all visible gaps.
Step Four – Installing The Pump And Skimmer
The submersible pump will provide the thrust to push water into the skimmer through the tubing and back into the pond. The submersible pump should be placed on the bottom surface of the pond.
The flexible tubing and power cable should first be fixed onto the pump before it is lowered into the water.
You want this to work well right?
Well the skimmer can be placed on a raised platform directly besides the pond. Fix it to the other end of the water tubing to connect it to the pump. Pile a few rocks on the edge of the pond to create a raised platform for the skimmer.
The skimmer has an outlet for releasing filtered water back into the pond. When positioning the skimmer, make sure that this water outlet is directed towards the pond.
You can connect the pump’s cable to a power outlet and switch it on to confirm that everything is working perfectly.
If you have filled the pond using water from a domestic supply line, it probably has a lot of chlorine dissolved in it. Chlorine is not healthy for fish.
And don’t forget:
You must therefore add a de-chlorinator into the pond to neutralize the chlorine. De-chlorinators can be bought at a farming-supplies store.
Step Five – Adding Water Plants And Fish
All that’s left now is planting some aquatic plants in the pond before introducing the fish. Although this step is not compulsory, there are several benefits of having aquatic plants such as:
Aquatic plants make your pond look more natural.
Aquatic plants provide shade for the fish to cool down when the weather gets hot.
These plants ensure that your pond doesn’t get overrun by algae.
Aquatic plants will also help in maintaining the oxygen concentration in the pond.
The most popular aquatic plants that you can consider planting include water lilies, lotus, water hyacinth and fanwort.
These plants should be planted in portable containers first. Once the plants have germinated, place these containers inside the pond on the shelf that was designed for this purpose.
After placing the plants, you can proceed to the final step of introducing the fish. It is always advisable to go for fingerlings (juvenile fish) as opposed to fully grown fish. Fingerlings will adapt more easily to the new environment as they grow compared to adult fish.
Fingerlings are usually supplied in a transparent polythene bag which contains some water. Do not release the fingerlings into the pond immediately.
You must remember:
Fish are very sensitive to sudden temperature changes. You should first place the sealed polythene bag containing the fingerlings in the pond for about 30 minutes.
This will provide adequate time for the fish to acclimatize to the water temperature inside the pond. After thirty minutes have passed, release the fish into the pond and let them enjoy their new home.
Maintaining The Pond
There are a few basic steps you can take to ensure your pond flourishes:
The water level in the pond will gradually drop over time due to evaporation. This causes the mineral and salt concentration in the pond to rise to toxic levels. Ensure that the water level is maintained by regularly topping up the pond with clean water anytime you notice a reduction.
If you don’t have a skimmer installed in your pond, you should check the pond daily for any floating debris or leaves. Removing such material from the pond is necessary as they can cause water pollution, especially when they rot. Consider investing in a pond vacuum so you can do this quickly and easily
The water in the pond should be changed twice a year. This should not be done at once. Adding a large quantity of cold water into the pond in one go can shock the fish. This means: You should therefore change the water gradually, by only emptying half of the total volume of water from the pond before topping it up with fresh water. This partial change will be sufficient to keep the pond clean without shocking the fish or disrupting the biological balance of the pond.
Perform routine checks on the plumbing equipment, submersible pump and skimmer to clear any blockages and confirm that everything is working perfectly.
Sunken ponds are a potential drowning hazard for children, especially those under five-years of age. If you have young children around your home, it is advisable to simply avoid constructing a sunken pond.
If you do have to do this:
You must take extra precautions whenever children are around to avoid any accidents. For example, you can erect a perimeter fence around the pond to restrict access. Alternatively, you can construct a raised fish pond which is a safer option.
That should be all you need to know to help create and maintain a fish pond.
Trust me, you’ll be glad you did!
Want to learn more about building a fish pond? You can find further information here:
Steve is a one time gardening hater turned into gardening obsessive. This was all thanks to going to University where a two year stint spent transforming the previously horrific garden of the student house he lived in left him addicted to all things horticultural! Now with a new house in tow and due to some fortunate circumstances he is free to test out a whole host of gardening equipment. Find out more about Steve or drop him an email at firstname.lastname@example.org.