| An air dome is a chamber fed by an air pump and | | | | You may have to find a compromise between |
| its top surface is made from a porous membrane. | | | | aesthetics and an efficient system. The skimmers |
| It can be fitted on top of the bottom drain dome | | | | used in koi ponds are usually those manufactures |
| and when the air pump is switched on, it produces | | | | for the swimming pool industry. |
| a column of fine air bubbles that rise to the | | | | If the pond is to be sited in a leafy location, you |
| surface. | | | | may decide to opt for a purpose built skimmer |
| This causes a vertical circulatory action, with the | | | | with an extra large strainer basket. To supply a |
| result that solids in the water are drawn towards | | | | properly sized filter with the correct amount of |
| the drain, where they are pulled away by the | | | | water for efficient operation, and taking all other |
| pump. At this stage, it is also important to look | | | | factors into account, aim for a pump flow rate |
| closely at the position of the surface skimmer. | | | | that will circulate the pond volume once every |
| If you place it too close to a water return, it | | | | two hours. |
| could prove useless. Prevailing winds will also stop | | | | To achieve this with a pond of about 20 meter |
| a skimmer working efficiently if all the surface | | | | cubic, you will need a pond with a capacity of 166 |
| debris is blown to the opposite side of the pond. | | | | lpm. If two or more bottom drains are |
| Look at the shape of the pond and resite the | | | | incorporated to satisfy the flow conditions, you |
| skimmer if you have any doubts. If you are | | | | may need more than one pump. |
| planning a large pond, you may need two | | | | A final point to consider when choosing a pump is |
| skimmers to achieve the desired effect. Sitting | | | | the running cost. Some are more efficient than |
| the skimmer in the most effective spot may | | | | others and when the larger capacity pumps are |
| mean looking into its throat from your favorite | | | | run continuously, they can be expensive. |
| viewing point. | | | | |