Building a container pond

Container ponds for patios, decks, apartments and backyards have become very popular for someone wanting a water feature with little space available. Any container that is water tight will do and enable you to have an attractive combination of plants and fish. It’™s like having an aquarium outdoors and the same rules of maintenance apply.
 

The Container

Any type of container will work as long as it can hold water. Plastic tubs will bend and buckle under the weight of the water, and after an extended period of time will become very brittle under the sun. I like ceramic containers or wooden half barrels often called whiskey barrels. These barrels have a very rustic look to them that aesthetically fits in well with a garden landscape. It may or may not hold water, but the wood will swell up, and may contain contaminants so a plastic liner should be inserted. Both the barrel and the liner may be purchased at many home and garden stores. Ceramic containers should have no need for a liner and have as wide an open top as possible.
 

Water

The water must be chlorine free. A dechorinator will take care of it.
 

Substrate

Add two or three inches of pea size gravel. This will help to hold down the potted plants.
 

Equipment

The only equipment needed is some type of pump and filter to provide circulation and biological filtration. The plants will consume nitrate and ammonium, but only during growth spurts and growth may be stalled right after pruning. A sponge filter is an easy way to provide the filtration and circulation. It can even help aerate the water. Filters and pumps MUST be left running continuously in order to be effective. Some people add an accent light around or over the top for night time viewing. This is particularly nice if you are using tropical lilies that bloom at night.
 

Maintenance

Container ponds need regular cleaning. The filter or pump should be checked every couple weeks to remove anything that may be clogging the intake. The water level should be kept constant by topping off any evaporation. 30 to 40% of the water should be changed once a month, (make sure it is dechorinated)
 

Fish and Animals

Goldfish and mosquito fish would be the most appropriate. DO NOT put Koi in a container pond, even if they are babies. There are some other cold water fish that may do ok, but why bother. You will never be able to see them. Tadpoles, crawfish, and cold water freshwater shrimp would also work, but not in the same container!
 

Plants

Dwarf plants are the most ideal. There are basically three types. Rooted plants that have floating leaves; dwarf lilies mainly. Surface floating plants, and marginal plants that grow rooted underwater with leaves and stems growing straight up a good distance above the water. Depending on the size of your container, you may only be able to have one or two of each type. Most floating plants such as Water lettuce or Duckweed spread across the surface very quickly and you will need to thin out the plants frequently or they will block light for the rooted plants and you will not be able to see your fish. One floating plant on each side, a lily plant in the center, and a couple dwarf reed/rush type plants in the back would be typical.

Further information may be found in the article Plants for container ponds.