Wading into Water Garden

Article Tools

Image Gallery

Print

E-mail

Comments

RSS

The smaller the pool, the more likely it is to have problems of green water, excessive temperature fluctuation and inadequate oxygen for the fish. If possible, try to achieve a minimum surface area of 50 to 60 square feet.

Proportions and profile. Size is linked to depth. No matter how large the surface area is, if the pool is only 3 to 6 inches deep, it will be a disaster. The ideal depth of medium-sized ponds with a surface area of 50 to 200 square feet is 2 feet. Ponds less than 50 square feet may be 15 to 18 inches deep. Ponds larger than 200 square feet would benefit from a depth of 30 inches. The reason for these guidelines is related to the needs of green algae. Algae thrive in warm, shallow water in full sunshine. Deeper water allows for a greater volume of water that is not in the susceptible top 6 inches where the algae thrive in the warmer and lighter conditions. The larger water volume also acts as a buffer to rapid and frequent temperature fluctuations, which are detrimental to many forms of pond life.

The relationship of depth to surface area is only valid when a pool has near to vertical side walls. In pools with a shallow, saucer-shaped profile, the volume can be reduced by as much as a half and an algae-free pool becomes more difficult to achieve because the water temperature remains more conducive to algae. Smaller ponds with marginal shelves all the way round the sides also have a reduced volume, so it’s better to restrict these shelves to where planting is necessary rather than build them around the entire pool. Ornamental ponds need be no deeper than 30 inches no matter how large the surface area.

Other Positioning Factors

With the concerns of size and profile in mind, the process of selecting the site for your water feature can begin. It might appear obvious to put a formal pool on the patio near the house or an informal pool at the lowest point of the garden, but to ensure that the best possible location is identified, consider the following points.

Shade. The pond should receive enough sunshine to warm the water and bathe the submerged plants in adequate light. The range of aquatic plants that can be grown in shaded pools is quite limited, and water lilies are reluctant to flower in these conditions.

Shade from trees is particularly troublesome because it is associated with leaf fall, which leads to a thick layer of decomposing vegetation on the pond bottom if not caught by netting (plastic mesh) placed over the surface. As this vegetation decomposes, it produces methane gas, which is harmful to fish. It is especially important to prevent the leaves of yew, holly and laburnum sinking to the pond bottom since they are poisonous to other plant and animal life in the water. Although conifers may seem to be less of a problem, their leaves are constantly falling and depositing fine dusty bud scales on the water surface.

RSS | Comments | E-mail | Print