Pond Design

So, you're no Frank Lloyd Wright. Well, who is? How are you going to plan a pond? We're going to take it step by step. The first and foremost step is planning. Planning and designing your pool is critical to the process of building a pond. Consideration must be given to the style of pond, placement of the pond, construction material, filtration, and ornamentation.

The style of pond that the enthusiast chooses is purely subjective, but must be considered at the start of the design process. It is generally recognized that there are two general types of ponds: formal and informal. Formal ponds follow geometric shapes and are generally inspired by the formal ponds built over the centuries in the gardens of Europe and the Near and Middle East. Japan is famous for its formal koi ponds.

A formal pond has a symmetrical shape, such as a circle, square, rectangle, oval, or octagon. They are often constructed of cement and don't contain many plants either in or around them. Instead, they generally have more visually formal settings like flower beds or green plants. They are generally placed close to the home where the fish are well attended and easy to see. These ponds are popular with some enthusiasts because they are simple to build and maintain. Others find formal ponds too stiff and conforming.

Things to Consider When Deciding on a Pond

  • Where are you going to place your pond?

  • Is there enough shade?

  • Is there enough light?

  • Do you want koi or goldfish?

  • How many fish do you want?

  • Is the pond the right size for the number of fish that you want?

  • Is it sufficiently deep to help your fish survive the winter?

  • Are there ledges or plants for your fish to seek shelter under?

  • What plants do you want in the pond?

  • Is there an electrical outlet somewhere near?

  • Where will you house the filter?

The other type of pond is informal or “free-form.” This style was developed in China, Korea, and later in Japan. There is very little symmetry to an informal pond and the shape is more natural. The idea is to try to recreate a beautiful, ideal setting that might be found in nature. The informal pond can take the shape of a kidney or any other free-form object. Some are constructed with cement, but durable synthetic liners are the material of choice because they conform to the curves and angles of the pond. Typically, informal ponds are rich in beauty and garnished with waterfalls, fountains, elaborate plantings (both inside and outside the pond), wood structures, stones, and a variety of ornaments. The informal pond setting, coupled with the beauty of koi or goldfish, creates a symphony of natural elegance that enhances any home and enchants even the casual observer.

Be Practical

Whether you choose a formal or informal pond depends on your personal preference, but be sure to choose a shape that provides good water circulation and prevents the development of stagnant areas. Elaborate pond design is an art form in some respects. For those who are so inclined, there are companies that specialize in the design and construction of ponds. Reputable experts not only assist you with the development of your pond, but they also make sure that your pond is properly plumbed to maintain very high water quality.

However, there are fantasy ponds, and then there's reality. Reality is better. Make sure you're not fantasizing about something that's so complicated you won't be able to maintain it once it's established. There have been many instances where hobbyists have built elaborate ponds only to find that they'll have to quit their jobs to maintain them. Don't fall into the trap of creating something too complex. Remember the old maxim—Keep It Simple, Stupid.

Where to Place the Pond

Placement, or site selection, is the most important part of installing your pond. This is a critical decision. You need to take into account a number of factors relative to water quality, fish maintenance, and fish safety.

Sunlight is both a gift and a curse. It is one of the most important aspects of siting your pond. Direct exposure to sunlight will elevate water temperatures in the pond to levels higher than koi or goldfish prefer. Neither fish wants to take a warm bath. In addition, sunlight will create algae. Small amounts of algae are beneficial to the pond by consuming nitrogen and releasing oxygen. And your fish will like munching on it. Excessive amounts will cause water fouling and oxygen deprivation. You want your pond to be placed in partial light and partial shade. That way it will warm the water slightly and give some algal effect, but it won't turn your pond into a swamp.

While it's a good thing to have some shade near your pond, it's not so much fun digging through very large, established root systems. Care should be taken not to site the pond too close to trees because root systems will not only make it difficult to construct the pond, but will eventually do damage to the structure of the pond, especially those made of cement. In addition, overhanging trees leach toxins and shed leaves that acidify the pond water and make pond maintenance more difficult.

I Fought the Law, and the Law Won

Wherever you site your pond, be sure that you conform with local zoning restrictions. Before you put one shovel into the earth, you should check with your local zoning board. Some towns or townships require permits before you add such an item to your property. Also, some require fencing, as they do for pools. So go to your local government seat, before they take you to one. Fines after the fact can be hefty, and some ponds have had to be filled in because they didn't adhere to local laws, especially in suburban neighborhoods.

Be sure to take into consideration the grade or slope of the land when you are siting your pond. The pond must be level, so extensive grading and sculpturing of the land may be required to achieve this. Take precautions to be sure that the area does not funnel water into your pond. Run off will destroy water quality by adding organic materials and toxic chemicals, such as fertilizers and pesticides to your pond. In some cases, heavily sloped land can be used to add a waterfall to the pond system.

There are many practical reasons to site your pond near your house. Your fish will get more attention if they are living close to where you are living. Logistically, if the pond is close to the home, it will be close to water and power sources as well. The closer the pond is to your house, the cheaper it will be to construct because it reduces the need to move water and electricity great distances. Having the pond close to your home may also deter common predators like raccoons and birds from consuming your fish.

Pond Size and Depth

The first question you have to answer is what kind of fish are you going to put in your pond? Goldfish or koi? The size of your pond will be directly related to the size of the fish. If you're thinking of a large pond, you probably want koi. If you're thinking of a small pond, then you probably want goldfish. Putting as large a fish as a koi in a small pond is like placing it in solitary confinement. The fish will go nuts.

Diagram of a Pond

If you're going to choose koi, make sure you really think out the size of the pond you've envisioned. All too often, the first pond of the koi enthusiast is too small. That is why every effort should be made to build as large a pond as possible the first time. Pond expansions can be a difficult and expensive task. A small pond is more difficult to maintain, and you are restricted in the number of koi that can be kept. Small ponds are fine to maintain if you're going to fill them with goldfish. Koi are large and can foul a small area quite easily. Koi experts recommend that the minimum surface area for a koi pond be 150 square feet. That's about 15 feet by 10 feet. That's a big pond, and it will hold a good number of koi. If that sounds way too big for you, then you need to think about goldfish.

The number of fish that you will be able to maintain in your pond is directly related to the size of the pond and the surface area. Koi and goldfish require adequate space to swim and sufficient oxygen to live; both are dictated by the size of the pond. The oxygen content of water is related to the surface area of the pond and the temperature of the water. Warmer water has less oxygen than colder water. Since ponds are maintained outside and most do not have heaters, the amount of oxygen in the pond is dictated by the season and time of day. There are times when oxygen is limited in the pond. The more surface area a pond has, the more room for gas exchange at the surface, and the more oxygen entering the water and toxic gases leaving the water.

A general rule of thumb is 30 square inches of surface area per 1 inch of fish. Therefore, a 150-square-foot pond (21,600 square inches) can hold approximately thirty-six 20-inch koi. When making this calculation, always take into account the maximum size that your koi will attain and not the size that they are when you buy them.

Koi vs. Goldfish

Maybe you've been dreaming about koi for some time now. Koi can grow quite large, and they need lots of room to maneuver. They can foul small pools quite quickly and that makes maintenance difficult. It also makes for lethargic and unhappy fish. If you've got the room and the desire, by all means go for it. But if space is a concern, maybe you should reconsider.

Goldfish are just as colorful as koi, and only half the size. Still, goldfish can grow to be quite large. Large enough, maybe, for what you were envisioning. Read both sections if you are undecided.

Even though surface area is important, adequate depth is also a necessity. The depth of the pond required depends greatly on your local climate, but deep water is integral to maintaining healthy koi and goldfish. The depth of your pond should vary in a shelf-like fashion. Ponds with a uniform depth pose problems relative to temperature fluctuations and predation. Deeper ponds do not have as much temperature fluctuation as shallow ponds, which is often more important than absolute water temperature. Deep ponds also provide better protection from predators such as herons, raccoons, and cats. Koi and goldfish are healthier if provided with vertical swimming activity as well as horizontal swimming area. Deeper ponds will not freeze in the winter, thereby allowing you to keep your fish outside throughout the year.

Some experts feel that a pond depth of 8 feet is ideal for fish, especially koi. However, since both fish are naturally bottom feeders, many feel that the enthusiast will rarely see the fish in a pond this deep. The shelf-style or terraced pond with gradually changing depth is a logical compromise to this dilemma. The shallow zone should not exceed 20 inches, sloping into water with a depth of five feet or more, depending on the severity of the winter. Shallow areas should slope at a steep angle into deeper pond zones. A deep central zone will accumulate debris which can easily be removed. The range of depths will serve multiple purposes. In the shallow zones, plants can be maintained and koi can be fed. In the deeper areas, the fish can seek refuge from predators and extreme heat, and they can hibernate below the ice during the winter months.

  1. Home
  2. Tropical Fish
  3. Ponds and Water Gardens for Goldfish and Koi
  4. Pond Design
Visit other About.com sites: