Backyard Pond Ideas: 12 Designs From Tub Ponds to Koi Ponds

Quick answer: Match the pond to your yard and your winter plan. Start with a 4-by-6 liner kit for a first water garden. Use a basin 3 or 4 feet deep if you want fish outdoors all year.

Start with a 4 by 6 by 2 foot liner kit; winter fish need 3 or 4 feet of depth. This page is a design-selection brief from our research desk. We did not dig a hole, stock fish, or run a water-quality trial.

Our research team analyzed published kit sizes and extension depth rules and did not rank products or split them by price.

How these 12 designs were selected

A design made this page only if a homeowner can start it from a currently sold kit or a listed liner size.

We also required a published depth or volume number from a maker page or from Oklahoma State University Extension. We left out swimming ponds, farm stock ponds, and indoor aquariums.

Pond terms beginners need first

A backyard pond is a lined hole or a tub that holds water on purpose. The liner is the rubber sheet that stops water from soaking into soil.

A pump moves water, and makers rate that flow in GPH, which means gallons per hour.

A skimmer is a box at the water line. It catches floating leaves before they sink. A BioFalls box sits at the top of a small waterfall, where bacteria break down fish waste.

UV-C is a lamp inside some filters. Laguna’s Pressure-Flo PF1000 page says the 13-watt lamp is there to inhibit algae.

Head height is how high the pump must lift water. Aquascape’s EcoWave 2000 page lists 2,020 GPH at zero lift and 860 GPH at 5 feet of lift.

Twelve designs from tubs to koi ponds

These 12 designs run from a patio tub to a deep koi basin.

Patio and tub ponds

1. Stock-tank tub pond. Use a round stock tank as the bowl, then add a small pump and potted plants. Oklahoma State University Extension says a fully above-ground pond may need to be drained in winter.

2. Half-barrel patio pond. Use a watertight half barrel on pavers, and keep it plant-only if the deck is old. The U.S. Geological Survey Water Science School lists water at 70°F as 62.300 pounds per cubic foot.

Liner kit ponds

A liner pond is a hole lined with rubber. Aquascape’s DIY Backyard Pond Kits page lists 45 mil EPDM liner. Underlayment is the fabric pad that protects that rubber from rocks.

3. Small 4-by-6 liner garden. Aquascape lists the 99763 kit at 4 by 6 by 2 feet. The liner is 8 by 10 feet, and the underlayment is 80 square feet.

4. Mid 6-by-8 liner garden. Aquascape lists the 99764 kit at 6 by 8 by 2 feet. The liner is 10 by 12 feet, and the underlayment is 120 square feet.

5. Large 8-by-11 ecosystem pond. Aquascape lists the 99765 kit at 8 by 11 by 2 feet. The liner is 12 by 15 feet, and the underlayment is 180 square feet.

All three kits share a Signature Series 200 skimmer, a Signature Series 1000 BioFalls, and an EcoWave 2000 pump. A 2-foot kit pond is a water garden, not a winter koi pond in a cold state.

Raised, formal, and feature ponds

6. Raised formal rectangle. Build a box of block or timber, set the liner inside, and use the same winter plan as any above-ground pond.

7. Above-ground viewing pond. Use a tall wall so you can watch fish at waist height. See our above-ground koi pond guide for the wall layout. Oklahoma State University Extension says a garden at least two-thirds below ground stays cooler in heat.

8. Stream-and-waterfall pond. Add a short creek that spills into the main bowl. Aquascape includes 25 feet of 1.5-inch pipe in each DIY kit for that spill.

9. Plant-first wildlife pond. Skip koi and use goldfish or no fish. Oklahoma State University Extension says floating plants should cover 50 to 75 percent of the surface.

10. Bog-shelf filter pond. Cut two or three plant shelves about 12 inches wide. The same Extension page describes that tier method for potted lilies.

11. Japanese-style viewing pond. Keep the bowl simple, with stone, one bridge, and few plants, using a liner kit for the hardware.

12. Deep koi pond. Dig a basin with a 3- or 4-foot-deep pocket. Oklahoma State University Extension says that pocket should not freeze and should give koi a cool retreat. Pair it with our koi fish care notes before you buy fish.

Laguna’s ClearFlo 1000 page lists four pump-and-filter kits for ponds up to 1,000, 2,000, 3,000, or 4,000 U.S. gallons. Use the larger kits on a deep koi bowl.

Kit hardware compared by published attributes

These five products are sold on their maker pages. The table uses listed attributes only, with no rank and no price.

Product	Role	Listed size or volume	Max depth	Liner	Pump or UV
Aquascape DIY Backyard Pond Kit 4 × 6 (99763)	Pond kit	4 × 6 ft	2 ft	8 × 10 ft, 45 mil EPDM	EcoWave 2000
Aquascape DIY Backyard Pond Kit 6 × 8 (99764)	Pond kit	6 × 8 ft	2 ft	10 × 12 ft, 45 mil EPDM	EcoWave 2000
Aquascape DIY Backyard Pond Kit 8 × 11 (99765)	Pond kit	8 × 11 ft	2 ft	12 × 15 ft, 45 mil EPDM	EcoWave 2000
Laguna ClearFlo 1000 Kit (PT1741)	Pump and filter kit	Up to 1,000 U.S. gal	Not listed	None	Max-Flo 600 and Pressure-Flo 1000
Laguna Pressure-Flo PF1000 UVC Filter (PT1725)	Pressurized filter	Up to 1,000 gal	Not listed	None	13-watt UV-C; 3 foams

Aquascape’s EcoWave 2000 page lists 65 watts and a 14.4-foot max head. Laguna’s Pressure-Flo PF1000 page lists a unit 13 by 13.7 by 15 inches and 11.5 pounds. The ClearFlo 1000 kit page lists a 3-year warranty.

The Aquascape kits build the hole, while the Laguna kits clean an existing hole.

Three worked yard examples

These are paper layouts built from published sizes and weights.

Worked example A: a 10-by-12-foot paver patio

The owner wants water, not a dig, so design 1 or 2 fits.

Keep the tub under 4 cubic feet of water if the deck is old. At the U.S. Geological Survey’s 62.300 pounds per cubic foot at 70°F, 4 cubic feet of water weigh about 249 pounds.

Do not set a 2-foot-deep kit pond on that patio. Aquascape’s 4-by-6-by-2-foot kit is 48 cubic feet, or about 2,990 pounds of water at the same USGS figure.

Worked example B: a 20-by-25-foot suburban side yard

The owner wants a first in-ground pond, so design 5 fits.

Aquascape’s 8-by-11-by-2-foot kit uses a 12-by-15-foot liner so the extra sheet can wrap the edge.

That bowl is 176 cubic feet if it is a true 8-by-11-by-2-foot box. At 62.300 pounds per cubic foot, the water weighs about 10,965 pounds.

Call the utility company first. Oklahoma State University Extension says not to dig over utility lines.

Give the pond at least 6 hours of sun. Keep the hole away from large trees so roots cannot punch the liner.

Use the kit skimmer and BioFalls, then follow a written pond maintenance schedule.

Worked example C: a 30-foot backyard that will hold koi

The owner wants koi outdoors all year in a cold state, so design 12 fits. Designs 3 through 5 do not, because those kits stop at 2 feet of depth.

Oklahoma State University Extension uses a 9-by-15-foot garden as its worked example, a surface of 135 square feet. The same page stocks one 12-inch fish per 4.5 square feet if the pond is not aerated. That load is 20 adult koi at 18 inches each.

Dig a 3- or 4-foot-deep pocket in that bowl. Add a catch basin 6 to 12 inches deeper still, which the Extension page says gathers fish when you drain.

Pair the bowl with a Laguna ClearFlo kit sized to the real gallon count. The ClearFlo 1000 page stops that model at 1,000 U.S. gallons.

Step up to the 2,000, 3,000, or 4,000 U.S. gallon kits if the bowl is larger. Measure length, width, and depth first.

Depth, fish load, and weekly care

Oklahoma State University Extension is the depth rule we used. Many year-round outdoor gardens need a section 3 or 4 feet deep.

In the deep South, 18 to 24 inches can work. That shorter depth needs few fish and plenty of floating plants.

Ponds deeper than 18 inches may be an “attractive nuisance” for insurance. The same Extension page says to check the insurer and to use GFCI outlets, which cut power if a cord gets wet.

Stock light. The Extension page gives this unaerated rule:

One 12-inch fish per 4.5 square feet of surface
Or, for a tighter hobby rule, 6 inches of fish per 5 square feet

If a fountain or waterfall aerates the pond, the page allows one fish per 2 to 3 square feet. Start lower than that max, because fish grow.

The same page also lists these care numbers:

Fish grow stressed when dissolved oxygen falls below 3 ppm
Fish can die near 1 ppm
A pH swing from 6.5 to 9 will not harm the garden
Alkalinity above 20 ppm is adequate; 50 ppm or more is better
Cover 50 to 75 percent of the surface with floating plants
Plant submerged bunches at one bunch per 2 to 3 square feet
Flexible liners usually last 10 to 20 years

Koi can live 60 or 70 years on that page. Read koi fish care before you add a second fish.

After you pick a design, use our pond maintenance schedule for weekly and seasonal tasks.

Call utilities and mark the dig zone.
Lay a hose to test the shape.
Check the insurer if the pond will be deeper than 18 inches.
Pick a kit whose listed size matches the hose outline.
Set the pump on a GFCI outlet.
Wait to add fish until the water is dechlorinated.
Net leaves each week and rinse filter foam when the flow drops.

Oklahoma State University Extension says city water must be dechlorinated before fish go in. Sunlight for one week can clear liquid chlorine. Chloramine needs a chemical dechlorinator.

FAQ

How big should a first backyard pond be?

Start with Aquascape’s 4-by-6-by-2-foot kit if you want a complete liner set. Step to the 6-by-8 or 8-by-11 kit if the lawn is open.

Can I keep koi in a 2-foot kit pond?

Not as a year-round outdoor plan in a cold state. Oklahoma State University Extension wants a 3- or 4-foot-deep section that does not freeze. Aquascape’s DIY kits list a 2-foot max depth, so use those kits as water gardens.

How much does the water weigh?

The U.S. Geological Survey lists 62.300 pounds per cubic foot at 70°F. Aquascape’s 4-by-6-by-2-foot kit is about 2,990 pounds of water. The 6-by-8-by-2-foot kit is about 5,981 pounds.

Do I need a filter if I have lots of plants?

Oklahoma State University Extension says a plant-heavy garden with few fish may not need a filter. Most first ponds still use one. The Aquascape kits include a skimmer and a BioFalls.

Where should I place the pond?

Give plants at least 6 hours of sun. Keep the hole off utility lines and out from under trees. Oklahoma State University Extension also wants a view from the house so you can spot predators and check the pump.

Can I put a pond on a deck?

Only after you check the joists, because water is heavy. Use a small tub, not an 8-by-11 kit. See the above-ground koi pond page for wall builds that stay off the lawn.