Give your fish enough food so that they can finish within a few minutes and then you can remove anything uneaten. Discourage mosquitoes from breeding by providing good water movement.
Finding the Site, Choosing Plants and Fish. A water garden or a pond opens up a whole new world of planting and
landscaping. You can start small, with a hollowed out rock that catches rainwater or really get into it by having a large pond with water lilies, fish and fountain.
Before building your pond, do a little homework. Unlike regular gardening, where you can blunder your way through almost anything, a water garden or pond involves a greater investment of time and money.
Siting and Design. A natural looking pond should have sloped sides with terraces that step down toward the deepest area. This allows you to plant a variety of plant material and create different
habitats. In the northern areas a depth of 2 to 3 feet is usually necessary to ensure that the pond will not freeze solid in the winter.
If you live in a warm climate, where frost is not a problem, you can line the bottom of the pond with concrete, brick or even clay. Most gardeners and professional landscapers use a preformed liner made from fiberglass or plastic, or a bendable, cut to fit liner made from PVC or butyl rubber. The preformed liners are quicker to install, but the flexible liners allow for much greater creativity.
For something on a much smaller scale, you might consider a patio water garden. Many aquatic plants can be grown in an old tub of water on your deck, balcony or concrete
patio. You can use an ordinary whiskey barrel lined with plastic or purchase plastic tub designed expecially for a water garden. You can put soil into the bottom of the container and plant right there or submerge pots filled with all different kinds of water plants.