2torial #0693:
Learn2 Build a Garden Pond (continued)

Line and fill the pond

A liner will help make your pond a relatively contained ecosystem by preventing water from draining into the surrounding soil, and earth from eroding and contaminating the water. Here's what you need to know regarding choices, size, and installation:

• Buy a liner specifically made for ponds (look under "aquarium" or "aquatic supply" in the phone book, or type it into your search engine). Other plastic or rubber materials can contain chemicals that will harm fish and plants.

• The liner length should equal the sum of the pond's length (including the shoreline), plus twice the pond's depth, plus an extra 2 feet (61 centimeters). Use the same method to calculate the width. If you have an irregularly shaped pond, use the maximum length, width, and depth in the formula.

• To install the liner, unfold and lay it evenly over the hole. Gently push it down to the pond's floor, then partially into the recess of the tiers (you don't have to push the liner tight against the surface; the water will take care of that). Be careful not to cave in any of the sides--using a broom to push in the lining will help you keep your distance from the edges. Place a weight (like a rock) on each corner of the liner, so it won't accidentally slip in when you add water.

• Lay the hose on the bottom of the pond and turn on the water. Make any necessary adjustments (unfolding kinks in the liner, and loosening it if it looks like it's stretching too much). Stop when the water level is about a foot (30 centimeters) from the surface level to allow room for rocks and plants.

Note: Much of what you'll put into your pond--including the amount of fish, water conditioners, and biological supplements--depends on how much water it holds. To calculate this volume, time how long it takes to fill it, from the first drop to the last. Then time how long it takes to fill a gallon (or liter) container using the same hose and water pressure. Divide the first time by the second time to determine volume.

• Once it's filled, trim the liner with scissors or a sharp knife, so its edge is a foot (30 centimeters) past the outer edge of the shoreline. Keep weights along the liner's edge so it doesn't slip in.

You're almost ready to start decorating. If you used tap water to fill the pond, wait a day before adding any plants. This time will allow the chemicals the water is treated with to partially evaporate.