– Pond Construction –

DSCN0340SO YOU WANT TO BUILD A KOI POND? Choose the Right Pond Builder! When selecting someone to build your Koi pond, the average landscaper or contractor probably will not know all the ramifications and intricacies of building a pond. It is not just a hole in the ground. If you are serious about raising Koi, willing to make the effort in time and money, you will want to see your “precious jewels” in a safe and healthy environment. On Golden Pond is happy to give you the following overview of the options you have and to guide you through the process, offering up-to-the-minute information to all your questions. The most important thing is for you to know precisely what kind of pond you want and how much money you want to spend. To do that you must be extremely well informed. Go to see other people’s ponds. Go to Koi clubs and talk to Koi enthusiasts. Come visit On-Golden-Pond. We are experienced in designing, building, maintaining and preserving Koi ponds. Some pond builders have only a few design options and all their ponds turn out the same. With today’s new technology, there are so many more ways of creating a pond that will represent your individual taste, as well as being easier to maintain and giving you better water quality than what was possible 5-10 years ago. Whoever you choose to design and build your pond, in order to avoid a disappointing experience and expensive disaster, you and your contractor must be clear on what you want. You need to be involved in the decisions. Needless to say, you must check out your contractor, get references from satisfied customers and see as many ponds as possible. Water Garden vs. Koi Pond After looking at all the options, some people decide to grace their landscaping with a water garden. These ponds are smaller and shallower (average 24 inches deep) and designed to enhance and fit in with the rest of the landscaping. It is usually filled with exotic water plants, waterfalls, gravel, rocks, boulders and set in a heavily planted garden. Water gardens are less expensive than Koi ponds because Koi need deeper, larger ponds to maintain their health and growth. They are built with multiple shelves of varying sizes. The “Marginal Shelf” is usually 2” to 8” deep to provide proper space for smaller water plants and bog. If you have Koi or large goldfish, this shelf is called by Samuel Toscano, the Feeding Station for racoons and herons or “The Sushi Bar”. The “Lily Shelf” is typically 10” to 16” deep for most water lilies. The deeper shelf, called the “Deep Area,” is usually 18” to 24” deep. The shallow depth of the shelves make it easier for predators like raccoons and blue herons to attack and devour Koi. The small size and relative shallow depth of water gardens, make them quicker and easier to install and do not require building permits. They are the safest of the pond types for children and pets. The shelves double as stairs if a child or pet should fall into the water. Generally, water gardens are filled with 3/8” to 1/2” pea gravel to hide the rubber liner. The pea gravel also provides a more natural look. Often contractors place aquatic plants directly into the pea gravel and think they do not need extra soil, pots or baskets. This is not good, however, because the plants tend to grow quickly and take over the pond. This requires a lot of maintenance and cleanups at least twice yearly. Water gardens need filters and pond skimmers to keep them clean. Pea gravel needs to be cleaned often. A net should be kept on hand to remove larger waste. To make this more efficient, a pond vacuum with a suction intake screen is often used. Goldfish and other small varieties of pond fish can live comfortably in a water garden. Koi, however, are another matter. They tend to outgrow a water garden in short order. Koi dive when they are threatened by predators. If a Koi cannot dive deeply enough, its stress level rises to unhealthy levels. This lowers its immune system, and a lower immune system leads to illnesses and infections. Koi also depend on speed to evade predators. Water gardens are not very large in relation to the speed a Koi can generate when fleeing a predator, and thus collisions with rocks and gravel occur. This can result in damage to the Koi, even death. A scraped and bruised Koi with damaged skin is susceptible to bacterial infections. Koi need deep ponds. The water pressure of deeper water helps the Koi’s internal organs mature properly. A water garden makes a wonderful meditation pool and can sustain small fish, but it is not a Koi pond. WHAT’S A REAL KOI POND? The rest of this article deals with details and decisions that need to be made with your contractor in designing and constructing a Koi pond. Design Decisions: Many times a first-time pond builder will decide skimp on the size of his pond in order to invest more money in Koi. After all, raising Koi is a primary financial commitment. He stocks his pond with a number of Koi that are 6” long. Everything goes well until three or four years later when the Koi are 24” long or more. It’s at this time, he will wish he had made his first pond larger. Another peculiarity of Koi is the deeper and larger the pond, the bigger the Koi will grow. On Golden Pond suggests a minimum depth of a 4’ to 5’ for the average pond. Koi can grow 20” to 22” in a 4’ pond. Jumbo Koi will grow up to three feet long in an 8’+ deep pond. Jumbo Koi are the champions that compete in Koi shows around the world and can be worth $100,000 or more. As mentioned elsewhere in this web site, there are pedigrees in Koi, but sometimes, when the breeders are culling out their stock, some fine specimens can slip through and are sold to pond owners. You can, therefore, buy a $50 5” Koi and it can, with time, care, and the proper environment, grow to become a very good quality Jumbo Koi. Check out the American Koi Clubs of America (AKCA.org) for more show Koi information. Another good forum that will give you even more web site referrals is www.Koi-bito.com. You might enjoy want to join a Koi club in your area where you learn from other Koi aficionados, such as www.znasocal.org, Zen Nippon AirinKai-SoCal Chapter. How Many Koi Can Live Comfortably in one Pond? It depends. A very general rule is one Koi for every 500 gallons of water, but this does not take into consideration how big the Koi are. You can easily keep thirty 6” long Koi in 1500 gallons of water. But two years later when those Koi are 18” long, things tend to get crowded. The number of Koi in a pond is limited by the filtration system. But even with good water quality, when Koi become too crowded their immune systems slow down and they could become ill. The best way to judge if the Koi are overcrowded is to observe if they are having difficulty swimming in a relaxed fashion. If they can’t, then it is time to remove some. Predators The shelves, so pretty in a water garden, are a predator’s stalking space in a Koi pond. The Koi’s brilliant colors are like bright neon lights that attract dangerous predators. Herons, raccoons, cats, foxes, badgers, weasels, kingfishers, hawks and hedgehogs are all capable of emptying a pond of its Koi. A pond must be structured with areas too deep for herons to stand in; overhangs too high for mammals to reach out and grab; and arbors or gazebos to block the aerial view of flying birds of prey. Sometimes it is necessary to string nets or wires above the surface to stop predators from reaching the Koi. The deeper and longer the pond, the better it is for Koi. Deeper ponds have less temperature fluctuation during hot and cold weather, as well as fluctuations between day and night. Shallow ponds heat up faster and cool down faster, causing a strain on the fish. Koi thrive in deeper water. They grow larger and put on more bulk. The longer the pond, the more room for the Koi to exercise and become stronger and more well developed. Koi sunburn easily, so a gazebo or arbor is essential for their tender skins. Pond Placement Koi ponds should be placed where you can enjoy them, as close to the house as possible, but not where it is accessible to the public or can be vandalized. Keep it away from deciduous trees and shrubs that will shed leaves and twigs into it. Make sure it is placed away from run-off water that might drain into it. Fertilizer from the lawn may wash into the pond during a rainstorm or regular irrigation, and this will kill your Koi and if not, it will serve as food for algae that could potentially choke and starve the filtration system. Keep drainage flowing away from the pond by a) making a 2” to 3” lip around the pond, and b) sloping the surrounding ground away from the pond. Shapes of Ponds There are two general types of ponds: formal and free form. The formal pool is a long rectangle; free form means the shape of the pond can be anything you want it to be, within certain limitations. One limitation is that there must be water movement in every portion of the pond. There should be no “dead” areas, where debris can collect. These areas of static water end up as a breeding ground for disease causing bacteria. The junction of the sides or corners should be rounded, not squared. This also prevents debris from collecting. The bottom of the pond should not be flat. The bottom needs to slope 20 to 40 degrees toward the bottom drain so that waste collect in an underlying sump or distal settlement tank. DO NOT PLACE SHARP OBJECTS IN THE POND. Rocks jutting out of the pond or lined around the edges of the pond will cause lacerations, bruises and cuts on the Koi, which can lead to infections and unattractive scars. Water plants in Koi Ponds There are problems with regard to placing water plants in Koi ponds. Plants often have parasites that must be treated with potassium permanganate before placing them in the pond. If parasites do get into the pond, it must be treated with harsh chemicals that are toxic to fish as well as plants. This means all the plants and fish must be removed before the pond is treated. After the pond treatment, the fish and plants must be medicated individually before replacing them in the pond. Generally, it is easier to keep the pond clean by eliminating water plants. Skimmers and jets tend to uproot and destroy plants anyway, thus making it necessary to scoop out the plant debris and Koi waste manually with a net, which is time consuming and tiring. Waterfalls, which create most of the oxygen in a pond, may be too rough on plants and uproot them. As mentioned previously, string algae are a regularly occurring nuisance in ponds. A commonly used method of killing string algae is to increase the salt level to .4 percent. Plants cannot tolerate salt at this level and will die. However, a well matured filtration system can withstand and keep algae under control. It is important to note, in the fall most plants die and create a big mess in ponds. Another disadvantage is that plants prevent you from seeing your fish. Koi tend to hide under plants, and this creates problems. They typically isolate when they are ill, and you may not notice this until it is too late to treat them successfully. When Koi reach 12” they like to eat the plants, leaving them chewed up and unattractive. Koi are also attracted to spawning and laying eggs that attach to plant leaves. People assume plants create oxygen and that this is good for Koi. Not so. Submerged plants, so-called oxygenators, provide oxygen during the day when there is sunlight, but they use up oxygen at night. The problems created are twofold: 1) the plants compete with Koi for oxygen at night, and 2) cause stress to the Koi by effecting rapid pH changes between day and night. Plants use carbon dioxide during the day, but excrete it during the night. We have an answer for those who insist on having plants because they devour nitrates that build up in the pond. A better alternative is to do partial water changes. A healthy pond develops a 3/4” layer of green algae on the walls. This algae feeds on nitrates too, and Koi nibble on it as well. For ease of maintenance, one can landscape around the pond with a variety of beautiful plants, yet with no plants actually in the water. It is still possible to have plants within the pond, if they are placed and cared for carefully. However, most committed Koi enthusiasts do not have plants in their ponds. This is a decision that you should discuss with your pond designer. A knowledgeable designer can work with you on the question of plants and your Koi pond. Underwater Lights in Koi Ponds Koi ponds take on a completely different and more dramatic look when lit up at night, and they enhance the pleasure of viewing the Koi. In designing the pond, the main decision to consider is the number, size and placement of lights for adequate viewing of the Koi. If there is only one light, there will be one light stream shining down the middle, leaving much of the pond in darkness. Lights should shine from various angles to thoroughly light up the water, thus brightly illuminating the Koi. Safety First Tip: Always use 12V underwater lights, such as LED, fiber optic lighting, or any other 12V light. Construction Decisions: The Pros and Cons of Rubber Liner vs. Concrete Ponds A 45 ml rubber liner pond is not as permanent as a concrete pond. It is also not as expensive. If you need to remove the pond totally, the rubber liner makes for an easier removal. The rubber liner offers a softer surface for the Koi, and the water pH tends to remain more neutral. Rubber liner ponds rarely require building permits. One minus to a rubber liner is that there tend to be folds in the bottom of the pond, even when the liner is properly installed. Once the pond is filled with water, however, the folds are less visible. Rock work around the pond is difficult, if you don’t want the liner to show. Rock work needs to extend below water level and mortar will not stick to a rubber liner. Cutting holes in liners for jets, lights, bottom drains, etc., can create problems unless you use bulkhead fittings. Liners can develop leaks, however, with proper installation and maintenance, liner ponds can remain free of leaks for many years. When choosing a designer/builder to install a rubber liner, check him out carefully. It is difficult to find an experienced, qualified builder to install rubber liners. Concrete Ponds Concrete ponds are more permanent than liner ponds. This is a plus if the pond is properly designed and constructed. If not, it can be a disaster and costly to correct. An added advantage is that concrete pond builders can and do use the expertise of professionals in the swimming pool industry to help with installing rebar and gunite. It is also easier to install rock work in a concrete pond. A possible disadvantage in new concrete pools is that it takes seven months for the pond to “cure” ecologically and there is a tendency for the water to have a higher pH. This problem is easily corrected by allowing the concrete to cure and then coating the bottom and walls up to the water line with a rubber base, epoxy, or a new, cutting edge technology, polyurea spray elastomer. Polyurea is fast drying, has no VOCs; it is seamless, durable, and can be applied to any thickness. Concrete cracks and rubber liners split and tear, but polyurea is resilient and generally wears better, lasts longer and camouflages mechanical equipment in your pond better than other coatings. Polyurea is applied at 175 degrees Fahrenheit. It dries tack free in under one minute, and the pond can be filled in 24 hours with water and fish. It has the ability to stretch approximately 700%, or seven times its original size. This product was tested for 75 years, at which time the test stopped, but the Polyurea had endured. Therefore we can offer a 20 year leak free warranty when using polyurea spray on liner. A concrete pond is easier to clean because of the contoured walls leading from the top to the bottom drain. The main disadvantage of a concrete pond is it is relatively expensive to build. You will probably need a permit for it. The upside to a concrete pond is bank appraisers think of concrete ponds as similar to swimming pools, thus adding value to your property. They equate liner ponds with portable swimming pools, and thus less valuable. Filters: the Heart and Lungs of the Pond Pre-Filter. Before debris, leaves, string algae and fish waste drift to the main filter, it is important to consider a pre-filter. These devices are designed to collect these materials before they reach the main filter. In small ponds, skimmer baskets and pumps may be enough. In larger ponds, with gravel filters (that are changed only once or twice a year), pre-filters are indispensable. The more waste pre-filters eliminate, the less you have to change the gravel filters. There are several types of pre-filters. Two examples are: 1) A simple holding tank of concrete or fiberglass, containing rows of brushes or mat material suspended in it to collect debris. This pre-filter requires you to regularly remove and clean the brushes or mat material. 2) A Vortex pre-filter is shaped like a round tub tapered at the bottom. Water enters from side openings at an angle, which causes the water to rotate in the tub. The debris drifts to the outer wall, then sinks to the bottom of the tank where it can be drained. Clean water exits from a pipe in the center. Pre-filters have their place in various types of ponds, but they are not meant to be used alone or instead of a regular filter. 3 Types of Filters It has been mentioned that the filtration system is the heart and lungs of the pond. It is more than that, it is also the blood flow of your pond. In order to understand this statement it is important to understand the nitrogen cycle that occurs naturally in all nature and specifically in Koi ponds. Healthy Koi are hearty eating machines that also poop and pee. Their waste is primarily ammonia that is excreted through their kidneys and gills. Ammonia also accumulates through other waste, such as dead leaves and other organic debris, undigested food, dead insects, and bird poop. An over abundance of ammonia can cause Koi to suffer from a reddening of their skin and impairment of their gills. A Koi suffering with ammonia toxicity will lie on the bottom of the pond in isolation, secrete excess slime, cease feeding and lose immunity to bacterial and parasitic infection. In extreme ammonia toxicity the Koi will die. Ammonia is mainly converted to Nitrite by Nitrosomonas bacteria. Nitrite is mainly converted to Nitrate by Nitrobacter bacteria. Nitrates are mostly harmless, unless allowed to increase to very high levels. Nitrates at normal levels are consumed by algae, plants and Koi like to nibble on plants and algae, thereby completing the cycle. Most importantly, Nitrates are washed away by frequent water changes. The filter keeps a Koi pond clear, clean and free of chemical pollution. It is important to think of filtration in terms of three major systems: Mechanical, Biological and Chemical. Three systems that provide three major benefits: optimal performance, ease of maintenance and cost effectiveness in both initial and long-term operating costs. 1. Mechanical Filters are devices that physically remove debris by trapping particles, large and small, from water passing through it. The water itself will not be treated and will still contain toxins and harmful substances. Because of this, mechanical filters should be used in combination with the other filters listed below. Examples of some of these devices are indicated in the section on pre-filters, such as canister filters and skimmers, as well as the following: Settling (Sedimentary) filter, a pre-filter; Vortex Settling Tank, a pre-filter; Sieve filter, Mechanical Strainers; Cartridge filter, Sand filters. 2. Chemical Filters are used to eliminate pesticides, odors, organic waste, excess nutrients, green water and other harmful chemicals. Zeolite and Coconut Shell Carbon are examples of chemicals that aid equilibrium in the pond ecosystem. Other chemical filters include Ozone Generators. As the name implies, this generator produces ozone, which at the right amount can kill algae, germs and bacteria, both pathogenic and beneficial. Careful use is strongly recommended if you choose this type of equipment because improper use of the ozone generator can kill your fish. 3. Biological Filters aid the naturally occurring nitrogen cycle by using specific bacteria to break down toxic waste to less harmful substances: 1) breakdown of ammonia to nitrite by Nitrosomonas bacteria, and 2) conversion of nitrite to nitrate by Nicrobacter bacteria. Biological filters provide devices and media on which these beneficial bacteria can grow. Foam, matting, gravel and beads are some of the media used. Biological filters take weeks to mature the healthy bacteria. Cultures of nitrifying bacteria are available to speed up the process. Examples of biological filters include: Bakki filters, Bead filters, Bioreactors, Fluidized Bead filters, Bubble Bead filters, Rotary Drum filter, Trickle Tower filter. Obviously, there is no one perfect filter. Components from each can be selected to provide optimum performance, ease of maintenance and cost effectiveness. Ultraviolet Lights As mentioned above, new ponds need up to seven months to become ecologically mature. In addition to pH factors, algae blooms can turn a clear, clean pond into thick, green muck. Ultraviolet lights kill any algae floating in the water. When algae pass through the unit, they are exposed to a bright ultraviolet light. The energy from the light destroys the DNA in the algae which causes them to die. As algae cells die they stick together and can be easily filtered out of the water. The size of the light is important. If the light is not big enough for the pond, the process will not work. If the water flow through the light is too fast, there will be reduced efficiency and produce little effect. Note: ultraviolet lights are not effective against string algae because such algae attach to the pond and do not flow through the light. In addition, they kill suspended good bacteria. In order to kill harmful parasites, you need very powerful output. Most importantly, there must be excellent water quality to reduce disease problems. Ultrasonic Algae Control Another boost for the elimination of algae in ponds consists of ultrasonic sound waves at beneficial vibrational frequencies that pass through most of the water in a pond and cause vacuoles inside the algae cells to resonate and break down, thus killing the algae. The cells of the green water algae are very tiny, and the sound waves move through them quickly. Once the pond algae is destroyed, it does not regrow. Used with beneficial bacteria, ultrasonic systems speed up the process of algae elimination. Scientific tests have been conducted and prove that sonic devices have no effect whatsoever on fish and other aquatic wildlife. Fish have been observed swimming up to the sonic device, curiously examining it, and then swimming unhurriedly away. Ultrasonic devices are cost effective treatments for algae. They limit biofilm and surface algae as well as underwater string algae, and kill root parasitic fungi like Pythium and Fusarium. While they do not provide aeration, they work well with aeration devices and beneficial bacteria products. They have low power consumption and are solar capable. For all its positive aspects, ultrasonic devices will not work on all algae all the time. It is highly effective on string algae, planktonic (green water) algae and floating algae. There are, however, literally thousands of species of algae, some with plant like structuring, which include macrophytic algae like Chara that will not be harmed by a sonic wave. Filamentous algae (string or hairy algae) form thick masses that can be destroyed by sonic waves, but it may take weeks or months for the sonic waves to work through the masses. Tests have reported that ultrasonic algae control systems work well on common types of algae, and will limit or put an end to the use of chemical applications. Used with underwater aeration and beneficial bacteria, ultrasonic systems will work well to keep your pond clean and clear. Protein Skimmers Protein skimmers have been used in salt water tanks for many years, but recently they have also been used in Koi ponds. They create foam which traps the dissolved organic carbons, or DOC’s. The foam is collected in a waste basket from which it can be disposed. Jets Jets have benefits for your Koi and pond. The natural habitat for Koi is a running stream. With the water current provided by jets, the Koi swim more, build up strength and improve their shape (body conformation) and increase their health and resistance to disease. Installed properly, jets can direct leaves, waste and debris to the skimmer and bottom drain, making it more effective. Another plus, as the jets break the surface of the pond, they trap considerable amounts of oxygen, increasing the level of oxygen in the pond. Bottom Drain A bottom drain is essential to a Koi pond. It is important to get fish waste into the filter so it can be removed as quickly and efficiently as possible. Without a bottom drain, the best filter cannot do its job properly. Some builders may try to tell you that you do not need a bottom drain. Placing rocks on the bottom of the pond will generate beneficial bacteria just like in nature. The only thing wrong with this reasoning is that in nature fresh water constantly flows through streams or rivers, and the fish population is usually one fish per 30,000 gallons of water, at the most. Koi ponds are much smaller, the fish population denser, averaging an optimal one fish per 250 gallons of water. It is also important to note that water in the Koi pond is filtered and used over and over again. What works in nature does not work in ponds. Skimmer A skimmer makes the difference between enjoying your Koi pond or dreading to look at it. A skimmer collects, in a basket or a net, leaves and other detritus that fall and then float on the surface of the pond. Without a skimmer you will have an almost full time job cleaning your pond by hand. Skimmers are a bargain, considering how inexpensive and cost-effective they are. They also reduce the strain on filters, pumps and your back. Even if you build your pond indoors, where there are no leaves, you still need a skimmer. Skimmers constantly sweep the surface of the water to remove debris, dust and bubbles (foam). Pumps A pump has one purpose: to move water. How much water needs to be moved? In large Koi ponds all the water needs to move through the pump every three hours. In smaller ponds the water moves in a shorter time. The general rule is to measure the total volume of water in the pond, and divide it by how often you want all the water to go through the filter. This figure gives the minimum water flow needed from your pump. After figuring this, consider the head pressure. How much pressure, at the minimum water flow, is created by your filter, jets, the height of the waterfall and plumbing? Confused? Take all these measurements to your pond builder, and he’ll figure it out. Another consideration: how quiet should a pump be? Unlike swimming pool pumps, pond pumps work day and night. Note: Do not try to use swimming pool pumps. They are not designed to work 24 hours a day. If you use one, this inefficient (for Koi ponds) pump will cost you at least $100 or more per month in electricity. The pipe size you use with your pump is extremely important. The smaller the pipe you use, the more pressure it will take to move water through it. Swimming pool builders usually use a smaller pipe size because it is cheaper and easier to work with. (Again, swimming pool pumps are usually on only 4-6 hours a day.) This is not so with Koi pond builders. Pumps are rated by how much water they can move, in gallons per minute, at a certain amount of head pressure. One foot of head pressure is the amount of pressure it takes to move one foot of water vertically. If the size of the pipes is increased, the head pressure drops. The lower the head pressure, the smaller, more efficient and less noisy pump can be used. This can save a great deal of money over time. This is why it is so important to plan all plumbing and filtration design from the beginning. Autofill An autofill keeps the level of water in pond at the same level at all times. As water evaporates, it will automatically be replaced. It is also useful when backwashing the bead filter or while performing routine water changes. The autofill will replace the water used during the process. Before dismissing this little gem and deciding to use the garden hose, be aware you need to add a dechlorinator to neutralize the chlorine and chloramines, which are toxic and lethal to fish. Chlorine and chloramines are the number one killer of fish in ornamental ponds. The number two killer of fish is ammonia poisoning. With an autofill you will never need to worry that you forgot to turn off the water and thus be confronted with a pond full of dead Koi. Under normal circumstances, you do not need to use a dechlorinator with an autofill because it is only replacing a small percentage of water each time from evaporation. Automatic Feeder Automatic feeders take a little pressure off you. Koi like to be fed at the same time every day. If you have a large pond, and you want your Koi to grow as fast as possible, get an automatic feeder and feed them a high protein food five times a day. Remember, though, during winter Koi eat little or nothing at lower temperatures, and even regular feeding can irritate their stomachs and make them ill. They also require low protein and high carbohydrate feeds during winter months. While automatic feeders are convenient, you will be missing a a time of pleasant interaction with your Koi. Around feeding time the Koi will swim to you, jump out of the water, and some times allow you to pat them. You will get to know them, know how they respond to you, and how they respond to the food. If one or more Koi are responding differently to you or the food, you will know something is wrong. Perhaps it is something as easy to remedy as the water chemistry being off. It could be something more serious such as parasites. If one of your fish does not appear for feedings, you can search and find him. Koi isolate and hide when they are unwell. Whatever the problem, you will avoid making it worse by spending time with your Koi and being observant. Regular hand feeding, even if it is only once a day, will allow you to get to know your Koi and deepen your enjoyment of them and your pond. If you’d like more information contact On Golden Pond at 310.922.5817 or e-mail us at samuel@ongoldenpondec.com. We are here to help you.