Outdoor Ponds: A Step-by-Step Guide to Designing, Building, and Stocking Your Dream Pond

Backyard ponds are booming across Australia—and it’s easy to see why.

In fact, a Great Australian Backyard Survey found that 79% of Aussies are planning new outdoor projects, and over 80% say their backyard plays a key role in choosing a home.

I’ve seen this enthusiasm firsthand—busy families spending evenings by the water, couples enjoying the gentle sound of koi, and wildlife finding a home in suburban paddocks. Outdoor fishponds aren’t just a landscape trend, they’re thriving ecosystems that connect us with nature and bring balance and serenity to our everyday lives.

At Aquascape, we’ve helped thousands of Australians realise their pond dreams, from cosy courtyard features to grand koi displays. Our high-quality liners, pumps, and decorative accents are built to endure the Australian climate and help you enjoy your pond without the fuss.

In this guide, I’ll walk you through everything you need to create your own outdoor fishpond—from picking the ideal location and liner to stocking it with fish and maintaining tip‑top water quality.

Let’s get started.

Outdoor Ponds and How to Build Them

When people ask me where to start with building a pond, I always say: begin with the vision.

What are you hoping to create—a peaceful spot to unwind at the end of the day? A lively backyard fishpond full of colour and movement? Maybe you’re dreaming of a pond that attracts frogs, birds, and butterflies to your garden.

Whatever the goal, the type of pond you build will shape every decision from here on—your layout, your liner, even the fish and plants you choose.

What Is an Outdoor Pond, Really?

In simple terms, it’s a man-made pond designed to hold water outdoors. But it’s more than just a hole in the ground—it’s a living, breathing system. A properly designed pond balances water, filtration, plants, and animals to create a beautiful and functional ecosystem.

You’ll hear a few different names thrown around: garden ponds, koi ponds, wildlife ponds, backyard fishponds. They’re all variations on the same idea, just tailored to different needs.

Here’s a quick breakdown of the common types of pond:

• Garden pond: Mostly decorative, these ponds are all about the plants: water lilies, marginals, and lush aquatic greenery. Perfect if you want a beautiful feature without fish.
• Backyard fishpond: Probably the most popular style of pond. A mix of plants and fish, designed for low-maintenance enjoyment and a bit of biodiversity.
• Koi pond: A more advanced setup. These are deeper, often more formal in layout, and built specifically to support koi—who need clean water, plenty of space, and robust filtration.
• Wildlife pond: No fish here—just plants, shallow shelves, and easy slopes so frogs, birds, and insects can come and go freely. These are fantastic for boosting local biodiversity.

No matter which style you go for, the magic happens when it feels like the pond belongs in your space.

Formal vs Informal: What’s Your Style?

One of the first choices you’ll make is whether you want a formal or informal pond design.

• A formal pond is structured. Think straight edges, perfect symmetry, crisp stone coping, and geometric shapes.
• An informal pond (or ecosystem pond, as we call it at Aquascape) is more natural. It’s irregular, organic, and designed to blend into your garden with rocks, plants, and flowing lines.

Personally, I’m a big fan of ecosystem ponds. The right balance of rocks, pebbles, plants, bacteria, and circulation means your water stays cleaner, your fish stay healthier, and you spend less time doing maintenance.

Building Your Outdoor Pond: Step-by-Step

Step 1: Choose the Perfect Location for Your Pond

When I help people design their outdoor pond, the very first thing I ask is: where do you want this pond to live? Choosing the right spot isn’t just about aesthetics, it’s about setting your pond up for success.

In my experience, partial sun is the sweet spot for most ponds. It gives your aquatic plants enough light to thrive without overheating the water, which can lead to algae blooms.

That said, if you’ve got the right filtration system in place—especially one tailored for Australian conditions—full sun ponds can work just fine. It just means paying closer attention to water quality and shade options.

But there are a few natural challenges to watch out for:

• Runoff: Make sure your pond won’t collect dirty water from gutters, garden beds, or roads. Contaminated runoff can introduce chemicals or excess nutrients that upset the balance.
• Tree roots: They’re a common culprit behind punctured liners or cracked edges. Plus, falling leaves and twigs create extra debris and maintenance.
• Overhead debris: Consider where leaves, branches, or even bird droppings might fall into your pond. Minimising these will keep water cleaner longer.

Accessibility is key too—make sure you can easily reach your pond for regular maintenance, and that you have a nearby power supply for pumps, filters, and lighting.

Step 2: Decide on the Right Pond Size and Shape

Next up is size and shape. This really depends on your available space, budget, and what you want from your pond.

Smaller ponds are easier and cheaper to build and maintain, plus they suit tight spaces. But they can limit your fish selection and plant diversity.

Larger ponds, while more costly upfront, offer room for more fish, plants, and features like waterfalls or islands. They also tend to be more stable ecosystems, with better temperature and water quality control.

When it comes to shape, I always recommend Sketching your ideas with a garden hose or spray paint. Irregular, organic shapes feel more natural, especially for informal or ecosystem-style ponds. But if you’re going for a formal look, clean lines and geometric shapes might suit your garden better.

And don’t forget about depth and tiered shelves—these provide important zones for plants and fish, and help keep your pond healthy.

Step 3: Pick the Best Pond Liner for Your Build

One of the most important decisions you’ll make is your pond liner. It’s the barrier that keeps water where it belongs.

You’ve probably seen preformed plastic ponds, which are simple but limited in shape and size. For anything larger or custom, flexible liners are the way to go.

From my experience, EPDM pond liners are hands down the best choice for outdoor ponds and outdoor fish ponds here in Australia:

• UV-resistant: They stand up to harsh Aussie sun without cracking or degrading.
• Long-lasting: Expect 10+ years of reliable performance with minimal maintenance.
• Easy to shape and install: Their flexibility means they fit irregular pond shapes perfectly.

If you’re searching for outdoor fish ponds for sale or liners to upgrade your existing pond, keep in mind that quality materials are worth the investment for durability and peace of mind. At Aquascape, we offer a range of EPDM liners tailored for different pond sizes and projects, making it easy to find the perfect fit.

Check out our guide to finding the best liner for your pond

Step 4: Install Your Pond Liner and Build the Basin

Once you’ve picked your liner, it’s time to dig in.

Start by excavating your pond according to your planned shape and depth. Remember to include shelves for plants and fish areas. Keep vertical walls straight for easier rock placement and structural stability.

Next, lay down a protective underlayment fabric over the soil to guard your liner against punctures and reduce underground pressure.

Then, bring in your EPDM pond liner. Start from the bottom and work your way up, gently shaping it into the contours of your pond. Don’t rush this part—the better your liner sits, the less likely you’ll have problems down the track.

Here’s where a lot of DIY builds fall short: Before adding any rocks or pebbles, cover the liner with a second layer of underlay. This protects the liner from sharp edges and helps your pond last for years without leaks or damage.

Now it’s time to start shaping your ecosystem. Add larger rocks around the edges and river pebbles across the floor and shelves. This isn’t just for looks—rocks give beneficial bacteria a place to live, which helps keep your water clear and healthy without relying on harsh chemicals.

Finish by securing the edges of your pond. Whether you go for natural boulders, stone coping, decking, or pavers, this final touch ties everything together and holds your liner neatly in place.

Step 5: Add a Skimmer, Filter, pump and optional Automatic Dosing System

Water circulation and filtration are the lifeblood of a healthy pond.The skimmer removes floating debris like leaves, helping prevent water quality issues and reducing pump clogs.

The biological filter—like a Biofalls unit—supports beneficial bacteria that break down waste, keeping your water clear and balanced.

A good rule of thumb for pump sizing is to match the flow rate (liters per hour) to your pond’s volume or filtration needs. Mechanical filters catch debris; biological filters handle waste breakdown—and together they work best.

For busy pond owners, Aquascape’s Automatic or Smart Dosing Systems make adding beneficial bacteria easy and foolproof, keeping your ecosystem humming along with minimal effort.

Step 6: Choose Plants and Ornaments for Oxygen, Shade & Style

Plants do more than just look good—they oxygenate your outdoor pond, provide shade, and help control algae.

Here are some of my favourites:

• Oxygenators: Hornwort and Anacharis oxygenate the water, essential for fish health.
• Floaters: Water lettuce shades the pond surface, reducing algae growth.
• Marginals: Water iris and Pickerel Rush add height and habitat around the edges.

Decorative elements like driftwood, rocks, garden ornaments, aquascape lighting, and spillway bowls can turn your pond into a true backyard masterpiece.

Step 7: Select the Best Fish for Your Outdoor Pond

Fish bring life and movement to your pond, but choosing the right species is important, especially for Australian conditions.

I usually recommend hardy species like:

• Australian natives - Rainbow fish, Silver Perch, Pacific Blue eyes
• Goldfish and Shubunkins
• White Cloud Mountain Minnows
• Pygmy Perch
• Koi (legal in WA and NSW)

A general stocking guideline is to allow plenty of litres per fish to avoid overcrowding, especially in new ponds.

Step 8: Fill and Cycle Your Pond Water

Before adding fish, it’s important to cycle your pond properly.

Start by filling your pond with water treated using a dechlorinator to safely remove harmful chlorine and chloramines. This step ensures the water is safe for your future fish.

Next, give the beneficial filter bacteria about 2–3 weeks to establish themselves. During this time, monitor ammonia and nitrite levels to make sure your pond’s ecosystem is ready for fish.

To speed up this process, you can use Aquascape Pond Starter Bacteria. It helps quickly establish the biological ecosystem for new ponds and spring start-ups by supporting the nitrogen cycle and promoting clean, healthy water conditions. Pond Starter Bacteria is safe for fish, plants, pets, and wildlife, and can be used in water temperatures of 5°C and above.

Starting your season with Pond Starter Bacteria means less time maintaining your pond and more time enjoying it!

Step 9: Maintain Your Outdoor Pond with Minimal Fuss

Good pond and fishpond maintenance is all about keeping things simple but consistent. Maintaining your pond doesn’t have to be a chore.

• Weekly: Remove debris, check your pump and filter, top up water, and add bacteria treatments.
• Seasonally/Annually: Trim plants, check for leaks, and clean filters.

Balancing shade, nutrients, and oxygen helps keep algae at bay.

And a proper EPDM installation means your pond setup will last longer with fewer problems.

Build an Outdoor Pond That Lasts for Years with Aquascape’s Pond Products

Building your dream outdoor pond is an exciting journey—from picking the perfect location and sizing your pond right, to choosing the best liner, installing a reliable pump and filtration system, selecting the right plants, and stocking it with healthy fish. Each step matters when it comes to creating a beautiful, balanced fishpond that you can enjoy for years to come.

At Aquascape, we understand that quality materials and expert advice make all the difference. Our range of premium pond liners, pumps, filters, and accessories are designed to help you build an outdoor fish pond that’s not only stunning but also built to last.

Cutting corners with cheap products might save you money upfront, but investing in top-tier products means less maintenance, better water quality, and a healthier ecosystem over the long haul.

Ready to build your backyard oasis? Explore Aquascape’s premium pond range and get started on creating a water feature that transforms your outdoor space and stands the test of time.

Outdoor Pond FAQs

Q1. Do outdoor ponds need a pump or filter?
Yes! A pump and filter are essential for keeping your pond water clean, clear, and healthy. The pump circulates water, while the filter removes debris and supports beneficial bacteria that maintain a balanced ecosystem.

Q2. Can you build an outdoor pond in full sun?
You can, but partial sun is generally best to prevent excessive algae growth and overheating. With the right filtration and shading plants, a full-sun pond can still thrive.

Q3. Do you need approval to build a pond in Australia?
This depends on your local council regulations and the size of your pond. It’s always a good idea to check with your local council before starting any excavation or water feature installation.

Q4. How do I prevent mosquitoes in an outdoor fishpond?
Good circulation and filtration, along with introducing fish, help keep mosquito larvae under control. Regular maintenance to remove stagnant water and debris also reduces mosquito breeding grounds.

Q5. Are backyard ponds safe for kids and pets?
With proper design, safety measures, and supervision, backyard ponds can be safe for families and pets. Installing barriers, keeping water clean, and educating children about pond safety are important steps.