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Water Feature Knowledge Base - Need to Know (NTK)


Leak Detection see TROUBLESHOOTING
Leaf Trap Cleaning see POND OVERVIEW.




Nitrification is the process where the ammonia in the fish waste and other decomposing organic matter is converted to nitrites and then nitrates. Both ammonia and nitrites can build up and become toxic to the fish. Nitrates are a harmless form of nitrogen that can be taken up by plants.



An overflow is the means to remove access water such as in a rain. The size of a pond largely dictates the need and size for an over flow pipe. Small ponds usually don't need an overflow. If the water level gets too high, the pond will find its own way to get rid of the water. When installing the liner behind the cap rock, it is easy to determine the overflow level. Larger ponds that have a Pool miser automatic filler have a 1" overflow built in if it is properly installed. For ponds of 300 sq. ft. or larger, we recommend an additional overflow. In a concrete pond it is easy to run a 1-1/2" or 2" horizontal or vertical pipe through the concrete and hide it between rocks. In liner ponds, use a 1-1/2" tank fitting to go through the liner. The final water level is easily adjusted with fittings.

is an essential gas dissolved in water. We insure adequate oxygen in pond water by the tumbling of the water over the waterfall. For times we do want to use the waterfall, we can use a venturi to oxygenate the water.



Pipe size is determined by how many gallons need to pass through the pipe. It is essential to have proper size pipe. If there is any doubt, up size. For ponds up to 3000 gal+/

  • we normally recommend a 1-1/2" intake and return pipes. This assumes there is not too much spaghetti (90° elbows) in the system or distance between the pond and equipment. If there is a lot of spaghetti or long distances involved, upsize the pipe. Up sizing is more important for the intake than the return. For a pump 1 hp. to 2 hp., use 2" pipe for both intake and return. For bigger pumps use 3" pipe or even bigger. At some point it may be easier to install two pumps rather than one big one.

    The principle pipe type used in ponds and fountains is PVC. PVC is a durable, cost effective way to move water. It is rigid, white and easily cut and glued. It is found in every hardware store. Some times in the pond we will use ABS black drain pipe for the after-market nicheless skimmer because it is the same color as the pond surface. But, we never use ABS under pressure.

    We do sell flexible PVC with its advantages and disadvantages. Flexible PVC is just that, flexible. We use it in tight spaces rather than a lot of fittings. Sometimes it is much easier to use flexible PVC going from the pump to the back wash valve. On the other hand, Flexible PVC is more expensive. Also, although we have never seen it, we hear from reliable sources that some kinds of termites love the stuff. We always wrap any flexible PVC going in the ground in Visqueen and seal the ends with duct tape. When used in conjunction with swimming pools with their short running cycles, flexible PVC can be abraided and damaged by repetative slight movement when the pump is turned on and off. Use the same Visqueen method as described above and surround the pipe with pea gravel. Also, when gluing flexible PVC to rigid PVC fittings, we use different glues than with rigid to rigid. Finally, flexible PVC can be damaged after long exposure to sun light.

    Copper pipe should never be used in conjunction with a koi pond because the copper is toxic to the fish. Also, just having copper pipe supplying the water to the pond can be a problem. This problem is more common for city folk because the soft, municiple water leaches out the copper faster than does well water.

    See the role of plants in the pond overview section. Plants are in a pond and are a nice transition between pond and surrounds. We suggest you get them from a reputable local nursery or mail order house. If you get them from friends, you increase the chance of bringing diseases and other unwanted things.

    Aquatic plants, especially floating plants, help trap nutrients in the water that would otherwise feed the algae. However, if you don't keep up maintenance, including dead heading, separating and trimming, the plants will fall back in the pond, decompose and become the same nutrients we are trying to get rid of.

    Pond plants come in three main types

    1. Bog plants tolerate soils with high water content but are not submerged. Bog plants are generally found on the edges of the pond or in very shallow areas where the water depth is 6" or less. Common bog plants are cannas, marsh marigolds, taro, some bamboos, pickerel, umbrella plant, papyrus, iris, cattails, and bullrush.
    2. Submerged plants have their roots on the pond bottom and the main part of the plant is under the surface, above the surface or both. Water lillies are a common submerged plant. Other submerged plants are floating hearts, yellow fringe, water poppy, snowflake and others.
    3. The third type of aquatic plants are the floaters. These plant float on the surface and take their roots with them. Common floating plants are water hyacinth, water lettuce, azolla (a small fern) and duckweed. We do not recommend introducing duck weed intentionally. It can take over and is hard to remove.

    Amaryllis- bulbs
    Baneberry- berries, roots
    Bird of Paradise- seeds
    Black Locust Bark- sprouts, foliage
    Boxwood- leaves, stems
    Buttercup- sap, leaves
    Calla Lily- leaves
    Cherry- bark, twigs, leaves, pits
    Coral Plant- seeds
    Daffodil- bulbs
    Datura- berries
    Death Camas- all parts
    Eggplant- all but fruit
    Elephant’s Ear- leaves, stems
    English Ivy- berries
    Hyacinth- bulbs
    Indian Turnip- all parts
    Iris- bulbs
    Jasmine- berries
    Java Bean- uncooked bean
    Lantana- immature berries
    Laurel- all parts
    Locoweed- all parts
    Marijuana- all parts
    Mayapple- all parts
    Mistletoe- berries
    Mock Orange- fruit
    Morning Glory- all parts
    Narcissus- bulbs
    Oak- acorns, foliage
    Pine- sap
    Poinsettia- leaves, flowers
    Potato- eyes, new roots
    Privet- berries, leaves
    Prunus varieties- seed, some parts
    Redwood- sap (from decks also)
    Rhubarb- leaves
    Ranunculus- all parts
    Snapdragon- all parts
    Snowdrop- all parts
    Tiger Lily- all parts
    Tomato- leaves


    is one brand of automatic fillers. It has an advantage over other styles because it includes an overflow. It has a float valve similar to what is in many toilet tanks. (In fact, if you ever have to replace it, look in your local hardware store). If the water level of the pond goes down, the float goes down and the valve comes on. The water flows though the pipe to the pond/fountain only because the slight difference in elevation. When the water level is equalized, the valves closes.

    It is necessary to install the Poolmiser during construction and have an 1-1/2" pipe, minimum, going into the pond about 16" below water level. It should be placed as close to the pond/fountain as possible with as few fittings as necessary. Usually this means one. If further than 15 feet from the pond/fountain use 2' pipe. The top of the Poolmiser needs to be set up about 3 inches above the water level. You can pass through the liner with a tank fitting. In addition, the Poolmiser has a 1" overflow and a combination 1/2" threaded and /3/4" slip supply fitting. It is covenient to have a valve on the water supply pipe near the Poolmiser.

    There are two ways of adjusting, gross or fine. For gross adjusting, turn off water, reach your hand inside the Poolmiser and feel under the float valve. From the bottom up, you will feel a threaded section that is inserted into the upper float assembly and held in place by a ring at the junction of the two parts. Pull up the ring. This will allow you to move the upper float assembly up or down. Replace ring. For fine tuning, squeeze the spring clamp on the float as is connects to the little wire and adjust the float up or down. If you can't adjust it enough, see gross adjusting.

    Troubleshooting If the Poolmiser is cycling (going on and off) either you have a leak or the pipe to the pond/fountain is partially clogged. Clean with a garden hose and then go to leak detection if necessary. If this happens from the beginning, you probably put too many elbows in the pipe or it is too far from the pond/fountain. Also, there is screen at the bottom of the grey filler pipe. Remove the float as described in coarse adjusting, unscrew the grey riser. Sometimes the screen will still be stuck in the bottom of the riser. If it is not, just turn the water on briefly and the screen will pop out. Then replace everything as you found them.


    Calculating the number of gallons in a pond is as much art as it is a science since we seldom have a nice, clean shape like a rectangle or cylinder. Therefore we have to estimate dimensions. Also, there are definitions we need to know so that we can use one of the mathematical formulas to figure the cubic feet in the pond from which we can figure the gallonage of a pond.

    • Pi(written ¼) =3.14.
    • There are 7.48 gallons in a cubic foot.
    • L = length, AL = average length
    • W = width, AW = average width
    • D = depth, AD = average depth
    • Since we seldom build ponds with straight sides we use a fudge factor such as .7
    • .85 to adjust for rounded corners and rounded bottom. The exact number to be used depends on how irregular the pond shape is and how steep the sides are.

    A round pond uses ¼ x radius squared x 7.48x7.5(fudge factor) = gallons.

    A rectangle uses LxWxDx 7.48x8.0 (fudge factor)= gallons pump.

    A kidney shape uses AL x AW x AD x7.48 x .70 (fudge factor)= gallons.


    Pressure gauges are often found on pressurized sand filters. They meassure the resistance to flow not the amount of flow. Perhaps this will clear things up. If you try to blow through a big straw, you can pass a lot of air easily. Now, if you pinch the straw and try to pass the same amount of air, you will have greater back pressure and your cheeks will billow out like Louis Armstrong's. In most systems, normal operation pressure will be 0-6 psi. The beginning pressure is not as important as changes in pressure. If you can see changes in the baseline pressure on the gauge atop a sand filter or cartridge filter, it is time to back wash or clean.

    The gauge is also good for detecting air leaks on the suction side. If the gauge jumps around you probably have an air leak. After you trouble shoot the problem and resolve the problem, the pressure gauge will remain steady.

    PRIMING THE PUMP See System Start

    We feature Sta-Rite and Maxiglas pumps because they are energy efficient and have their proven reliability. Pond pumps, unlike swimming pool pumps, are high volume, low pressure. Some of these pumps have two speeds. The low speed is used for daily use; a real energy saver. The high speed is used for back washing and occasional high volume times. see ENERGY CONSERVATION.

    For a pond, the pump size is primarily determined by the number of gallons in the pond and the hydrolic head (the resistance to flow). To ensure maximum efficiency of the system and pump longevity, the pump, filter, UV light, intakes and returns and pipe sizing must all be in balance. For a pond, we want to turn over the water at least two hours. Therefore, if you have a pond with 3000 gal. we want a pump that can deliver at least 25 gallons per minute. (We want to move 1/2 the volume in an hour. Dividing by 60 tells us we want 25 g/min).

    We must remember though, we need 25 g/min. after the water passes through the filter, UV light and plumbing. Therefore, we must select a pump, and all the equipment, that can handle the flow.

    NOTE: If you are replacing a pump, you can not necessarily install a bigger pump and expect more flow. You are limited by the size of the pumps that are installed. See Hydrology and Horsepower.

    Most projects, one pump is enough. On rare occcasion, you may want to go to two pumps rather than one one big one. If you decide to put in two pumps remember, if you put them in series (one after the other) you will get the same volume under twice the pressure. On the other hand, if you have two pumps in parallel, you will have twice the volume with the same pressure.

    For best performance, pumps should be installed slightly below water level and near the pond or fountain. This gives us a flooded suction. Pumps are designed to push water, not pull it. The pump can be two feet above the water level without effecting the efficiency. However, if the pump is much above the water level, the pump will be working under additional strain and the pump life will probably be shortened.

    The pumps may be covered but should be done so that it has plenty of air circulation for cooling and not in a sump where water could collect.


    It is much easier to install the wiring harness at the pump before it is in place. These suggestions as how to install the harness are generalized but should be useful. If you can't wire a switch or a plug, have an electrician do it. Its not worth the risk to you or the pump. All pumps and lights need to be grounded and protected by a GFI.

    You will need a 90° flexible conduit fitting, a length of flexible conduit and wire. Cut the flex conduit to the approximate length you require. From the info below, determine the number and color of wires required. The color, size, and number of wires required vary by number of speeds and voltage. Check instructions that come with the pump to determine the wire size. Most pumps can use 14 ga copper wire if the source is within 100' of the pump. However, we always use 12 ga. because its a little bigger. IMPORTANT The further away the electrical source, the bigger the wire size you should use. Undersizing wire can cause expensive pump repairs or replacement.

    120 volt one speed; 1 red or black, 1 white, and 1 green.
    120 volt two speed; 1 red, 1 black, 1 white and 1 green.
    220 volt both one and two speed; 2 black or red, 1 green

    If you twist the wires together and can keep the flexible conduit straight, you should be able to push the wire through the flex. If you are not able to get the flexible wire through, fish a piece of rigid wire through the flex conduit and connect it to the wires and pull. For longer runs, tie a small piece of sponge on a strong string and vacuum it through the conduit from the far end then tie and tape the wire to the string and carefully pull it through,

    • Remove the back plate from the pump.
    • Take the nut off the male threads of the 90 fitting. We use some kind of sealant like liquid electrical tape or plumber's putty on the threads. Screw the fitting in the hole on the side of the motor. Keep in mind which way you want the conduit to go.
    • Remove the nut, gasket and insert from the other end of the fitting. Slide the nut on the flex conduit first, then the gasket (make sure not to switch it around). Screw the insert into the end of the conduit. Feed the wires through the fitting. With the aid of a needlenose pliers pull the wire toward you.
    • Slide the conduit toward the fitting. Twist it slightly to insure the insert is properly seated. Pull up the gasket and tighten the nut.

    Wiring a one speed pump 120 volt pump is similar to wiring a switched outlet. There is one hot wire (usually red or black) that goes to one terminal on the switch. Another hot wire is connected to the other terminal of the switch and the hot terminal on the pump. The common (white) is connected directly to the common wire from the pump. The ground (green) should be pigtailed in the box and connected to the box and attached to the grounding terminal in the pump. After you connect the switch to the box, use a weatherproof switch cover or a weatherproof plastic cover.

    Wiring a 120v two speed pump is similar to wiring a one speed pump except we have an additional wire from the switch to the pump and requires grounding.

    If you have a Sta-Rite two speed pump, the instructions on the motor differ from the ones in the booklet, naturally. The easiest way to wire a two speed pump is with a single pole, double throw, three position maintained switch. That's a mouthful. You can make your own using a three position toggle switch but its a real pain. (We did it for years but its not worth the time and short life expectancy.) Basically what we use is a three position switch with off in the center and an 'on' above and below. The juice comes to the switch and can go out either lead to the pump. The two speed switching is then done internally. For a two speed pump, you will need four wires going from the switch box to the pump; red, black, white, and green. See two speed pump wiring harnesses. All two speed switches come with a wiring diagram. Simply, I have made it a habit to use red for 'high' and black for 'low'. That way when I'm wiring the switch, I don't have to remember which is which

    A two speed switch has four terminals:

    • high, red wire (brass screw)
    • low, black wire (brass screw)
    • power in (black screw)
    • ground (green screw)





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