Does your pond look dirty and is the water too murky to see plants or fish? This is a common problem in outdoor ponds where the owner has not bothered to install a bottom drain. A bottom drain helps keep your pond looking clean all year long because it is a great water clarifier.
It is generally accepted that bottom drains are a must and should be fitted to all ponds under construction but if you made your own pond with a plastic liner or basin you may have skipped this step. The good news is that it is never too late to install a simple one.
A bottom drain can also greatly improve the efficiency of any mechanical filter and especially a gravity filter. This can save you a lot of time when it comes to skimming or vacuuming your pond and the filters will just work better. The better the filters work the more oxygen there will be for any fish in the ponds.
If the main drain is above the height of the pond then it is possible to have a discharge chamber, and then you can pump the pond water to the drain, using a pump with a fitted float level. The float levels can tell you a lot about the health of the pond and whether it is time to give it a cleaning.
In general, bottom drains have a deep large sump usually 10 to 12 inches diameter and about 6 inches deep. These usually have a 4-inch socket to take pressure pipe and this is then taken directly to the drain box where a 4-inch standpipe with `O’ ring is fitted. It is also possible to purchase bottom drains made of fiberglass.
Most pond drains have what is called a mushroom cover. It’s called this because it makes the drain look like a large black or steel mushroom. The more bottom drains you have, the less maintenance your pond will require from you.
Usually, the number of bottom drains required will depend on the size and shape of the pond. A rectangular pond that is between 12ft x 10ft would probably require two bottom drains if you want the water to be as oxygenated and as clean as possible.
Each drain should have its own straight pipe that connects directly to the mechanical filter to keep your pond from looking as muck free as possible. This can save you from doing a lot raking of debris all year round.