A water feature in the backyard is not only an attractive way to add dimension and visual interest to the entertaining space, it can also be a tranquil, relaxing place to which to retire. A pond filled with marine plants or fish can be a welcome respite in the yard.

For those who haven’t done major excavation or built something similar in the yard before, it pays to become educated before digging the first hole. In order to ensure the fish pond goes in correctly, there are a few things the do-it-yourselfer needs to know.

* Determine size. Many first-time pond builders simply make their ponds too small. If fish or a lot of aquatic plants are planned, be sure to size it large enough to accommodate growth. Err on the larger size — some dirt can always be added back if it seems too large. A koi pond should be at least four feet deep at its deepest point. One can vary the depths of the pond by creating shelfs of dirt or rock.

* Determine location. The best place to put a pond is close to the house so that it can be enjoyed when someone is outdoors or inside. Also take into consideration rain run-off. This may contain chemicals from fertilizers and pesticides that can contaminate pond life. Avoid locating it too close to trees, otherwise a lot of time will be spent cleaning out leaves and other debris. If the pond will be growing only plants, be sure it gets a few hours of steady sun a day. For a pond containing only fish, shade will be adequate.

* Plan on water circulation. Although circulation is not a must, it can help aerate the water and clean out debris, if a filter is used. Plus, moving water is less susceptible to insect larvae growth like that of mosquitoes. Figure a waterfall or water jet into the design and a skimmer that will suck out the water. Be sure the skimmer is positioned so that the level of the pond water meets halfway up the skimmer box. If a waterfall will be used, gradually slope the pond away from the waterfall to direct water toward the skimmer. Check municipal building codes to see if a permit will be needed for the pond and the requisite plumbing/electrical work. There may be regulations as to how deeply the power line must be buried and other requirements.

* Purchase the correct liner size. Be sure to purchase the right size liner for the pond. Measure the maximum length and width of the pond. Double the depth of the pond and add it to these measurements. Add a foot or two for overlap and this will give you the pond liner size.

* Pay attention to rocks and gravel.Too much gravel at the bottom of the pond may cause noxious gases to build up that can gradually kill off marine life. Only put about 2 inches of gravel. Also, keep in mind that some rocks are better left out of the pond design. Limestone can affect the pH of the pond water making it very acidic. Try to make the pond look as natural as possible, hiding pipes and electrical switches with plants and other landscaping items.

* Fill and get started. Be sure to include some aquatic plants because those will help create the right mix of nutrients into the water that can feed fish and other plant life. There is also pre-packaged pond bacteria to prime the pond filter. Let the filter run a day or two before adding any fish to ensure that the water condition is right