Small Pond, Big Return

A water garden adds appeal to any yard, whether it’s a simple tub on a patio or a lavish in-ground pond with plants, bubbling fountains and darting goldfish.

“Water gardens are a refreshing retreat from the stresses of the harried world,” says Arnie McFalls of the Georgia-based National Pond Society.

Depending on your ambitions, however, creating one can be as consuming as any major remodel. McFalls suggests the uninitiated spend a year studying reference books, joining pond tours and consulting experts before putting shovel to soil.

But we’ll streamline that process by focusing on a garden pond that fits most yards and can be installed in a weekend. To start you off, we’ve provided expert advice from Charles B. Thomas, author of three water-gardening books and chairman of Buckeystown, Maryland-based Lilypons Water Gardens, the largest aquatic-plant nursery in the United States.

Putting in the Pond

You can tailor the size and shape of a pond to any garden or landscape. We chose a free-form, 5-by-10-foot pond that’s 24 inches deep--a popular size and satisfying choice for beginners.

“It isn’t too large for most yards and accommodates goldfish and a variety of aquatic plants,” Thomas says. No pumps or filters are required to keep the water clean and healthy, though you can always add a pump if you want moving water.

You’ll find everything you need--from the liner that contains the water to fish and aquatic plants--at garden centers or through mail-order specialists. The total cost is $200 to $300.

Locating the Pond

Look for a spot as level as possible for the easiest installation. “The more sun the better,” Thomas says, because waterlilies and other aquatic plants bloom best with six to eight hours of direct sunlight each day.

Avoid low-lying areas where runoff can flow into the pond. Also avoid areas below the water table--ground water will push up on the liner during wet times of the year. And be sure to pick a location within garden-hose length of a spigot so the pond is easy to fill.

Then think safety. Depending on pond depth, you might have to fence it in. Check with local building and zoning authorities about fencing requirements. Even if a fence isn’t required, enclosing the pond protects young children.

Also consider installing a moisture-proof outdoor electrical outlet with a groundfault circuit interrupter--essential if you decide to add a pump or decorative lights.

Choosing a Liner

Pond liners are either flexible or rigid. Flexible liners usually are made of PVC or synthetic rubber, while rigid liners are fiberglass or polyethylene. According to Thomas, 90% of first-time water gardeners pick the flexible type, and that’s a good choice.

Flexible liners conform to a hole of any shape or size, while rigid, preformed liners limit you to set shapes and sizes. Flexible liners also cost considerably less. A 45-millimeter rubber liner, which Thomas suggests for the 5-by-10-foot pond described here, costs $125 to $185, compared with three to four times that for a similarly sized rigid liner.

For durability, choose a rubber liner at least 45 millimeters thick or a PVC liner at least 20 millimeters thick. Be sure it’s manufactured for ponds and guaranteed safe for fish and plants.

To secure the liner, you’ll need enough to extend 6 to 12 inches beyond the excavated area. Calculating the proper liner size is easy: Double the depth of the pond and add that figure plus 1 foot to both the length and width of the pond. That comes to a 10-by-15-foot liner for a 5-by-10-foot pond that’s 24 inches deep.

Shaping, Digging

Once you have picked a site, outline its shape with a rope or garden hose. Thomas recommends a compact shape with gentle, natural-looking curves. This way, Thomas says, you’ll use the liner most efficiently with minimal waste.

Dig out the desired shape and depth. If you use a shovel, have someone help you to speed this phase of the process. Or rent a mini-excavator (about $135 to $175 per day). A depth of 24 inches is usually ideal. Water this deep stays more stable in temperature than shallower water does--cooler in summer and milder in winter, which is good for plants and fish.

Slope the pond sides gently outward as you dig to help keep mud and stones from sliding into the pond. Be sure the rim is level all around so water won’t spill from the pond or leave the liner exposed. Check it by laying a straight 2-by-4 across the excavation at various points and setting a carpenter’s level on the board.

Also create a 12-inch-diameter section of the bottom that is 1 to 2 inches lower than the rest; this small depression will help a pump do a better job of draining your pond if you add one.

Installing the Liner

Once the excavation is smooth and free of debris, protect the liner from punctures by adding a 1- to 2-inch-thick layer of sand to the bottom of the hole (about 7 or 8 cubic feet of sand for a 5-by-10-foot pond).

Line the pond edges with old carpet or a non-foam underlayment, a thick, felt-like material that costs about 25 to 35 cents per square foot.

Before laying the liner, open it and allow it to soften in the sun. “Don’t leave the liner on the lawn,” Thomas warns. “Heat buildup under the liner can kill the grass in only about 10 minutes.”

Spread it in the hole, making sure it overlaps the edges evenly. Again, have someone help you--the 10-by-15-foot liner suggested for this pond weighs about 35 pounds.

Smooth out the big wrinkles, and tuck and fold the liner to fit curves and angles. Place bricks or smooth stones around the perimeter so wind won’t blow the liner back into the pond.

Filling and Edging

Slowly fill the pond with water to within 1 inch of the rim; the water will make the liner conform to the contours of the hole. When the pond is full, trim off the excess liner, leaving a flap 6 to 12 inches wide to go beneath the edging.

Water-gardening books devote entire chapters to edging techniques. The easiest method is to lay flagstones or bricks on the flap along the perimeter of the pond. You can also mortar the stones or bricks together for added stability. If you do, drain the pool and refill it with fresh water; mortar dropping into the pond raises the pH of the water.

If you plan to stock the pond with fish, Thomas suggests adding a water conditioner, such as AquaSafe from TetraPond, to remove heavy metals and chlorine from the water. And if the water in your area contains chloramine, you’ll need a special formulation.

Plants and Fish

The right combination of plants, fish and snails does more than add life and beauty to a garden pond. “They maintain water clarity and ecological balance,” Thomas says.

Specialty catalogs and books provide simple formulas based on pond size for how much of each you’ll need. As a guideline, start by adding plants from each of the basic plant groups. Our pond holds three waterlilies, 25 to 50 bunches of submerged plants (six stems to a bunch) and five containers of floating-leafed and upright plants (three plants to a container).

Add goldfish a week after adding plants. Besides being entertaining to watch, fish consume algae and pests such as mosquito larvae. “Don’t overdo it,” Thomas cautions. “Having too many fish is the most common cause of murky water.”

Stock up to the equivalent of 1 inch of fish per 5 gallons of water--about 35 4-inch-long fish for this roughly 700-gallon pond. Also add one black Japanese water snail for every 2 square feet of surface--or 25 snails for this 50-square-foot pond. Snails eat decaying matter and algae off plants and pots.

Once you’ve stocked the pond, don’t be alarmed if the water turns a murky green. “New ponds go through a murky stage that may take four to six weeks to clear,” Thomas explains.

Instead, relax at the edge of the pond and enjoy your creation.

Reprinted from Today’s Homeowner magazine. To receive more expert advice on improving your home, call (800) 456-6369 or visit the Web site: https://www.todayshomeowner.com