Building a Backyard Pond? Here’s What You Need to Know First

Garden Pond Advice

I’ve had several different types of ponds over the years and no matter what size or style, the basic maintenance and care is all the same.

I’ll walk you through everything you will want to consider before building your backyard pond. These tips will help you avoid some common mistakes that are very hard to fix once a pond is built, and show you what is involved in caring for a pond so you can decide if it’s right for you.

Contents

Tips Before You Build a Pond

1  Legal

Check local bylaws to make sure you are indeed allowed to have a pond. And make nice with your neighbors so they don’t try and throw a wrench in your plans.

2   Safe

If there are young children around or pets that do not swim, ponds are not worth the risk. It’s a lovely addition to a garden but only if you are certain it’s safe.

3   Location

Ponds are best situated in the open, away from trees. Tree roots can be difficult to remove and can grow right back into your pond. Fall leaves will rot in the water, fall to the bottom, and create muck.

There are also some plants that are toxic to fish, so you will want to choose your plantings around the pond carefully. Bonnie Plants has a list here.

One huge mistake many gardeners say they made was putting a pond at the back of a garden, far from the house.

If possible, situate your pond where you can enjoy it from the house or patio.

This is also handy for daily checks to ensure everything is running fine.

And, this really pays off in winter when you have to be sure the pond is not icing over and killing your fish.

4   Access to Resources

Unless you are creating an all-natural, pump-free pond, you will need an outdoor GFCI (Ground Fault Circuit Interrupter) electrical outlet accessible to the pond area.

This should be installed by a licenced electrician to ensure it is safe and meets local codes.

Access to outdoor tap water is also needed, first to fill the pond, and then top it up on hot days when some water will evaporate.

A water outlet is also handy for routine maintenance like cleaning filters.

5    In-Ground or Above Ground

The next big decision is choosing whether you want an in-ground pond or to build one above ground in a container.

In-ground ponds can be more natural looking and are usually made by excavating the soil and installing a pond liner made specifically for this purpose.

Above-ground ponds can be built in any water-tight large container. These galvanized water troughs are a popular choice right now. This pond was built in an old hot tub.

I made my above-ground pond by building a raised garden bed and inserting a prefabricated pond form, also called a rigid pond liner.

You can also use pre-fab pond forms as in-ground ponds.

6   Pond Supplies

These are the basics:

• Pond liner (rubber liner and soft underlay) or preformed pond container
• Recirculating pump with (optional) fountain spout

Larger pond kits may come with:

• Skimmer box
• Tubing to connect skimmer to waterfall
• Spillway box (to create a waterfall)

You may also need:

• Rocks to line pond
• Leaf skimmer
• Ground Fault Circuit Interrupter) electrical outlet
• Outdoor water tap

This is the pond kit I got for building my large pond:

Where to Get Deals

• Off-season online classified ads
• End of season sales
• Look for kits instead of buying parts individually
• Yard sales
• Trash
• People getting rid of their pond – you uninstall it and it’s all yours!

7   Water

It’s assumed you have a clean water source to initially fill your pond. Most tap water is chlorinated, and it takes a day or so for the chlorine to off-gas.

Once you have fish, plants, and other wild things like frogs in your pond, adding tap water will be two-step process: first you fill a large tub and leave it for a day.

Then you can add the water to your pond, so you don’t risk harming any living things. You can also speed it up with dechlorinating tablets.

8   Water Pump

One of the keys to keeping a pond healthy with clear water is to have a good recirculating pump running at all times.

These pumps are made specifically for ponds. The motorized pump is submerged in the water, drawing water in and sending water out.

Some also have filters to help remove gunk from the water. Others are simply pushing the water around, to help keep It oxygenated.

See pond pump on Amazon.com

It is important to use a pump that meets the needs of your pond.

Pumps are made in different strengths, measured in gallons per hour (gph).

You want a pump that moves your total water capacity every hour, plus extra strength to lift the water through any waterfalls or fountains as well.

Example: a 2000-gallon pond with a waterfall three feet above the surface would need a pump that is at least 2200gph or perhaps 2500gph. A pond professional can help you choose what’s right for your specific setup.

I also always have a spare pump on hand in case my current one fails for any reason. This is not terrible in the warmer months but can be tragic in winter.

You have to keep the water circulating to ensure fish and frogs survive. If the water freezes, they are toast.

9   Aquatic Plants

Depending on where you live, there will be different choices for pond plants.

First, you’ll want to decide whether you want annual or hardy perennial water plants. I determine this by budget: annuals can be lovely, but they will not survive the winter. We have fewer options for hardy perennials beyond water lilies, but they last for years.

Some aquatic plants float on the surface, others have roots and grow in rocks or aquatic potting medium in baskets below the water surface.

Just like any garden, invasive pond plants can be an issue. There are plenty of fast-growing pond plants that will take over while your back is turned.

I’ve had some that I thought were doing fine until I went to move their root baskets (sitting a ledge in the pond) and discovered they had taken over like beasts, tangled up with other plants in the pond and completely wrapped around rocks in the bottom.

Eventually, there’s such a volume of plant roots down there that there’s no room for fish or water circulation.

A pond expert at a garden nursery can be a great resource for choosing the right plants.

A big part of the decision will be how much you are willing or able to maintain the plants to ensure they do not mess up your pond.

This articles showing how I built my inground pond shares the names of some of my aquatic plants.

10   Pond Fish 

If you live in a cold climate like I do, you will need cold-water fish for your pond. Koi and goldfish are popular choices but there are lots of things to consider first.

Big fish will eat smaller fish, so there’s that. And some different types will not get along with others.

Also, the number of fish you choose will depend on what their size will be maturity and the volume of water in your pond. A general rule is, allow 2 cubic feet minimum per goldfish to ensure their health and happiness. Koi require more space. This has a formula for how many fish to add to your pond.

Unless you keep your pond unnaturally clean, your fish will also breed, giving you more fish, so leave room for babies as well.

It’s best to find a local pond store that sells pond fish to get good advice on what to choose for your pond. And don’t add them until your pond has been established for at least few weeks or more.

Some pond owners feed their fish store-bought fish food. Mine live entirely off the pond itself.

When getting new fish, follow these instructions for safely introducing new fish to your pond.

Fish are really prone to shock, so you want any changes to be as gentle and gradual as possible.

11   Daily Maintenance

If your pond is well-built in a good location, maintenance will probably only be required occasionally.

I check my ponds daily to make sure everything is running smoothly, and the fish are happy.

If you feed your fish, you’ll want to create a routine where they get to know and trust you.

Some pond pumps have filters that will need cleaning out whenever gunk gets in them.

A skimmer tool is handy for removing any leaves or debris that has blown into the pond.

You may also need to top up the water on hot days due to evaporation. As mentioned, chlorinated tap water should be held in reserve in large open container for a day first to let the chlorine off-gas. Or you can use de-chlorinating tablets.

To help keep pond water clear, there are liquid bacteria products that boost the good bacteria in the water. These come in a squeeze pump and get added as needed according to the instructions.

The older a pond gets, the more it will naturalize, and this can mean algae will build up, especially in the hot weather. See How to Clear Murky Pond Water Fast—Without Any Chemicals for my trick to turn green water clear again.

12   Winter Maintenance

Winter pond preparation includes moving some hardy aquatic plants lower down in the pond, so the roots don’t freeze.

Cleaning out filters and removing leaves.

Making sure your fish will be safe by never letting the water freeze. I do this by keeping the waterfall running all year-round and adding a pond heating (floating de-icer) to prevent the surface from icing over. There are gases that build up from fish waste and these become toxic if they are not released into the air.

This has detailed advice on Caring for Your Fish Pond in Winter.

Frequently Asked Questions

1   How much does it cost to put in a pond?

The cost will depend on whether you are doing it yourself or hiring a company to build the pond.

A basic 1000-gallon pond kit is around $1,000US plus the cost of rocks and other landscaping supplies.

Hiring a professional pond-building company to create a 20×40 pond could cost you $20k or more.

2   Do you have to have a pump in a pond?

Unless you are specifically trying to create a natural pond with no circulation, yes, a pump is always recommended.

Pumps help keep the pond water clear and healthy by oxygenating it with constant movement.  This is better for fish, other wildlife in the pond, plant health, and preventing stagnant green water.

3   How deep does a fish pond need to be?

A good minimum is two-feet deep, and it’s very good to have areas at least four feet deep if you have fish, frogs, or turtles. The greater depth keeps the pond animals safer from predators. And, the deeper the water, the less likely it is to freeze up in winter. Keeping the water running in the cold seasons is essential for keeping fish and frogs alive. If it freezes, they do too.
4   How does a pond water pump work?

Pond pumps are designed to be submersed in pond water with an electrical cord that runs externally to a power outlet. These pumps draw in water through a vacuum action and send it out again, often through an output hose, or to a waterfall or fountain. Some water pumps also have sponge filters to collect gunk from the water as it passes through.

5   How much sunlight does a pond need?

The ideal location for a pond is in partial sun, but not under trees that shed leaves. Too  much sun encourages rapid algae growth. Too little sun and the aquatic plants will be slow to grow or flower.

I hope this has provided a good understanding of what’s involved in building and caring for a backyard pond.

Let me know if you have any questions, and be sure to sign up for the newsletter for more handy garden tips.

~Melissa the Empress of Dirt ♛