How To Build A Fish Pond Above Ground?

By Harry RamosLast update: 2024-06-18
How To Build A Fish Pond Above Ground?

Building a fish pond by yourself is not an easy task. This job doesn’t just require a lot of equipment, tools but also certain skills.

However, if you really want to have a fish pond of your own in your backyard, there are now means to help you do that. And the one means we can provide for you today is a step-by-step instruction on how to build a fish pond above ground.

We suggest that you read this post very carefully before getting started.

What To Prepare

There are several ways and materials for you to build a fish pond, but regardless of your choice, you still have to prepare the following basic things:

  • A pond skimmer

  • A back washable biological filter

  • A bottom drain pre-filter

  • A bottom drain

  • A UV clarifying system

  • An aeration system

Besides, you need to take note of the following things before starting setting up the pond.

  • The pond must be at least 4 feet deep

  • Prepare water circulation and turnover rate

  • Don’t use rocks or gravel in the pond

  • Don’t use sharp objects to avoid hurting the fish

  • Don’t use planted aquatics

How To Build A Fish Pond Above Ground

Building a fish pond is not hard, all you need is carrying out these procedures step by step.

Step 1: Prepare A Design

Create a rough drawing of your pond, which means you have to determine the length, width, and depth of the pond, as well as its shape. You also need to indicate the position of the filtration system.

For example, the 3-way flow control valve can be placed in a round valve box between the pre-filter and the skimmer.

The UV system can be placed in a rectangular valve box near the pre-filer and skimmer. You can put the external pond pump and bead filter near the pond, depending on the surroundings to hide the pump.

Then paint your design on the ground in the actual dimensions.

Step 2: Dig The Pond

How To Build A Fish Pond Above Ground?

You can consider renting a small excavator to reduce the workload, it’s also easy to operate, and allows for easy soil re-locating. Keep the re-located soil for later, you can use it to hide the US system, control valve, pre-filter, aeration system, and the skimmer, or create a flower bed at either end of the pond.

Use the excavator for heavy digging then use shovels to fine-tune the excavation, which should be 1 foot longer in all directions so you will have space for retaining walls.

Step 3: Set Up The Retaining Walls

How To Build A Fish Pond Above Ground?

There are different materials you can use for retaining earth like wood, concrete, and concrete blocks.

Place 4 posts at the corners of the pond, place additional posts in the middle if needed. Depending on the depth of the pond, dig the post holes deep enough for stability.

For instance, if the pond is 4 feet 6 inches deep, you should dig the post holes 18 inches down from the bottom of the pond.

Place the post in the post holes, fill the remaining space in the hole with concrete then place a soil layer over the concrete. Wait for the concrete to dry then attach the retaining wallboards to the post with stainless steel deck screws, which won’t corrode over time.

Once you have completed attaching the wallboards, you can fill the extra excavation with the re-located earth.

Step 4: Drill Holes For The Pond Skimmer And Water Returns

The pond skimmer should be located near a corner to maximize the current draw and surface circulation.

First, mark the spot where the inlet pipe of the skimmer will draw water from the surface then drill a hole through the retaining wall. Now, drill a smaller hole for the water return lines.

For the highest efficiency, you should place the water returns so as to create a circular motion. To do this, install the main water return at the opposite corner on the same end as the skimmer near the pond’s middle depth.

The UV return line should be installed on the other end of the same side you install the skimmer.

This will result in a circular “vortex” in the water current, hence the fish waste will drop to the pond’s center. This way, the bottom drain can get rid of the waste and pass it to the pond’s pre-filter.

Now, for the UV water return, you need to drill a hole in the opposite corner on the opposite end from the main water return.

You should locate it near the bottom to increase the current at the bottom and push debris away from the corners.

Step 5: The Bottom Drain

Locate the center at the bottom of the pond, dig a hole big enough for the drain along with a trench wide and deep enough for a 4-inch drainpipe.

Remember to dig under the retaining wall.

Level the drain in all directions to make sure it works properly.

Next, lay the aeration tubing side by side the bottom drain pipe and leave at least 18 inches of an aeration tube stub above the ground. Compact earth around the bottom drain, around, and on the drain pipe.

Step 6: Install The Pond Skimmer

How To Build A Fish Pond Above Ground?

Slip that remote installation pipe of the pond skimmer through the hole on the retaining wall. Apply silicone to the inside edge of the reducer coupler’s ends then slip the coupler onto the simmer inlet pipe.

Then, the remote installation pipe must be slid into the reducer coupler. You need to lock it in place with stainless steel nut.

Now, level the skimmer and slide the UV return pipe through the drilled hole on the retaining wall of the pond. Place the pipe in the space between the pond box and the excavation edge.

Extend a flexible PVC pipe around the retaining wall to where the UV clarifying system will be installed.

Attach a liner to the pipe the same as attaching the liner to the skimmer, using a stainless steel clamp and rubber collar.

Step 7: Install The Styrofoam System

How To Build A Fish Pond Above Ground?

Now that plumbing lines are through, under, and around the pond, you should cut the posts. Then, compact soil in the area outside the retaining walls.

Using stainless steel screws, install Styrofoam insulation on the inside of the retaining walls to protect the liner from wood splinters, ensure stable temperature, and reduce vibration.

Step 8: Hook Everything Up

Install the UV clarifying and aeration system to fit them in a rectangular valve box.

How To Build A Fish Pond Above Ground?

The skimmer’s UV pump outlet port must be connected to the first UV’s inlet. Then, the first UV’s outlet must be connected to the inlet of the second UV. Finally, connect the return pipe to the second UV’s outlet.

Attach the bottom drain pipe to the pre-filters outlet.

Connect the main pump outlet of the skimmer to one side of the flow control valve. Connect the outlet of the pre-filter to the other side of the flow control valve. Then, connect the valve’s outlet to the pipe running to the external pump.

Extend the main return pipe to the position of the pond filter for Koi.

Step 9: Prepare The Underlayment And Liner

Grade the pond’s bottom to make the bottom drain the deepest point and grade the earth upward and outward from the bottom drain. Remember to compress the soil as tight as possible.

The underlayment must be cut into pieces to fit the bottom and the sides, leaving holes for the skimmer inlet pipe, the two return pipes, and the bottom drain.

Now, install a fish safe rubber liner with the corners folded inward. You can also use other materials to hold water in the fish pond like polyuria, rubber, and concrete.

Then, attach the rubber liner to the skimmer remote installation pipe.

Step 10: Install The Air Stone Diffuser And Bottom Drain

Use your hand to find the basin of the bottom drain under the liner then cut an X in the center of the drain opening.

Put the gasket mounting plate over the drain basin, on the liner then line up the gasket’s screw holes with the drain basin.

Remove the mounting plate and apply silicone on the drain basin’s upper perimeter, then place the gasket plate back and install all the screws.

From the inside of the basin, cut out the liner and align the drain gate and install the two screes.

Next, attach the diffuser to the air tubing and place the diffuser on top of the drain gate.

Lock the liner to the retaining walls using a capstone or cap board.

Step 11: Install The Filter And External Pump

You can hide them behind bushes or however you feel suitable. You need to dig a trench to run the plumbing pipes from and to the pond.

Install the filter on a level firm surface.

First, connect the pipe from the flow control valve to the inlet of the external pump. Then, connect the outlet of the pump to the inlet of the filter. The filter outlet must then be connected to the pond return.

Next, you need to connect a pipe to the filter valve waste port and the auto-fill valve kit pipe must be connected to the water source.

Now, the auto-fill valve kit must be attached to the skimmer and its water supply pipe must be connected to the barb outside the skimmer.

Install the air pump in the same box as the UV clarifiers and connect the air pump with the air tubing.

Install the check valve of the external pump inside the pond skimmer. Attach the valve to the outlet port connected to the flow control valve.

Step 12: Complete Your Pond

Add final touches to finish the appearance of the pond. Add landscaping and decorate the pond the way you want.

How To Build A Fish Pond Above Ground?


As of now, we hope that you have figured out how to build a fish pond above ground. This means you should know what equipment to buy, what tools to use, and what you want the pond to look like eventually.

There are a lot of items and steps, a lot of work to do. If could be a small project you conduct with your family or by yourself though it may take more time to do this alone.

Good luck building your own fish pond!

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