How To Choose The Correct Pond Pump
Choosing a pump for your pond or fountain is a crucial step to ensure you maintain proper water movement. Failure to keep the water adequately circulated can result in stagnation, algae buildup, and mosquitoes. In addition, if you have fish, plants, or other aquatic life in your pond, you must keep the water healthy by evenly distributing the oxygen levels and other nutrients.
Types of Pond Water Pumps
There are two main types of pond water pumps: submersible and external (out-of-pond), also known as centrifugal pumps. Depending on the application, each pump offers specific advantages.
Submersible Pond Pumps
Submersible pumps are designed to be fully submerged underwater at the deepest part of the pond. They are placed directly into your pond or in a skimmer box or pond vault. Submersible pumps range in size from 50 to 5,000 gallons per hour. They are easy to install and are sometimes a more economical solution for smaller ponds (up to 1000 gallons of water). They are also quiet and can also be used to drain your pond. If you have fish or other aquatic life in your pond, you may want to consider a model that does not use oil because there is a danger of the pump seal breaking and oil coolant leaking into the water.
Centrifugal Pond Pumps
External or centrifugal pond pumps are a reliable, energy-efficient option. They are installed in a dry location near your pond. External pond water pumps are suitable for larger ponds (over 1000 gallons). Compared to a submersible pump, they are typically louder and more complicated to install; however, they are easier to maintain.
When selecting a pond pump, it’s essential to keep in mind that pumps have different cord lengths. Ensure the cord is long enough to go through the pond and plugin far away from the water. Some electrical codes specify that the outlet for water features must be at least 6 feet away from the water. Therefore, it is recommended that you avoid using an extension cord. However, if you must use one, make sure it’s suitable for outdoor use and plugged into a ground fault circuit interrupter (GFCI) so that it will immediately shut off if there is an overload.
How to Size a Fountain or Pond Pump
Pond pumps are sized by gallons per hour (GPH) at one foot of lift or height. Larger capacity pumps are rated by horsepower (HP). To determine the size pond pump, first, you need to calculate the volume of water in the pond. To calculate the volume of water in gallons, multiply the length x width x average depth x 7.5.
Water Circulation Factors
It is recommended that pond water is circulated at least once per hour. For example, if you have a 500-gallon pond, you need a pump that runs 500 gallons per hour at the discharge height. If your pond has a pressurized filter, you ideally want to turn the water approximately once every two hours. For example, if you have a 1000 gallon pond, you need a pond pump rated at a minimum of 500 GPH. If your pond has a skimmer or waterfall, the water should be turned approximately once every hour. Therefore, if you have an 1800 gallon pond, you will need an 1800 GPH rated pump.
Calculating Head and Lift Height
Two of the most critical measurements in sizing a pond or fountain pump are the maximum head height rating and maximum lift. Head height means the vertical height the pump raises water above the surface of the pond. The pond fountain pump’s top height can lift the water to is called “Maximum Head” or “Max Head.” The “Head” is measured straight up from the water level of the pond. Its length then measures any horizontal/diagonal flow, and 1’ of “Head” added per 10’ of horizontal/diagonal distance. To calculate the lift, you need to measure how far the water in your fountain has to travel from the pump’s location in your rush to the top of the fountain where the water comes out. Then you need to select a pump that lifts higher than that measurement. For example, if that distance is 24”, than you will need a fountain pump that lifts at least 36” tall. The “maximum lift” is the maximum height that the pump will raise the water.
Selecting the Proper Pond Water Pump Tubing
It is also essential to use the correct tubing size because it directly affects the pond pump’s maximum lift capability. If you use smaller tubing than specified, you will limit the pump’s maximum lift and the amount of water circulated.
Choosing the right pond water pump for your pond or fountain requires careful consideration and a little upfront research. However, doing so will go a long way toward keeping your water clean and healthy and your pump operating efficiently.
Facts: About Pumps
Not many people want to be involved in the mechanics of a pump because it can be too difficult to understand. But if you learn just a little it will help you understand the living, breathing ecosystem that is your pond.
Pumps and plumbing make up the circulatory system of a water feature. More important, they supply the system with necessary oxygen and keep the water circulating.
Water garden vocabulary:
GFCI (Ground Fault Circuit Interrupter) is designed to protect people and pets from severe or fatal electric shocks.
GPH – Gallons per hour. Means the gallons that the pump is circulating every hour and can be referred to as rated flow. Small to average water gardens and Koi ponds need to circulate every hour with a full exchange of the water in that hour. Larger gardens every 1 1/2 hour exchange.
GPM – Gallons per minute.
Pond Volume – The amount of water in a pond.
Formula for calculating the gallons in your pond.
- Irregular Pond = length x width x average depth x 7.48
- Circular Pond gallons = 3.14 x r2 x average depth x 7.48
Head Height – The height from the surface of the pond to where the water comes into the biofalls (usually at the bottom of the unit), which means the amount of elevation change a pump can take to pump water.
TDH (Total Dynamic Head) – The combination of the total height and the total run a pump has to push. Total dynamic head refers to the pressure on a pump caused by the interactions of flow rate, pipe diameter, pipe length, elevation, and pipe material.
The other contributing factor to the size pump you will need is the width of the waterfall when it enters the pond. You will need 1500 to 2000 GPH in a pump for each foot of stream width at the entry point into the pond basin. Large systems sometimes require 3000 GPH per foot especially if you want white water.
Basically, it takes all those things into account and lets you know the limitation of your pump.
Flow Rates – The amount of water moving in a given time period.
Mag Drive – Type of pump that relies on magnetic forces to drive the impeller. Pumps a smaller amount of water than direct drive pumps, but are more efficient and usually used for fountains and small basin applications.
Direct Drive – Type of pump in which a motor drives a shaft that spins the impeller. More durable than a mag drive and usually used to provide water to a waterfall.
Watts – Electrical power consumption of a motor. Watts = volts x amps
Amps – The rate of flow of an electrical current.
Check Valve – Valve that prevents water from back flushing from the BioFalls to the skimmer where the pump is located.
PVC (poly vinyl chloride) – A common thermoplastic resin.
All of the Aquascape and AquascapePro line of pumps are made specifically for water gardens. They are submersible pumps which also need to be placed in a skimmer or wet well.
Specifications can mean the difference between a gushing waterfall and a trickle that sounds merely like a leaky faucet.
Operating Cost
Look for high efficient pumps. Obviously the bigger the pump is, the larger your operating cost per month can be. High efficiency pumps use less power.
Waterfalls and Pump size
Establishing the flow rate for your pond is probably the most important thing to do when it comes to your waterfall.
Experts say that for each foot of spillway width as it enters the basin, you should allow 1500 to 2000 GPH. For example, a 2 foot waterfall width usually requires between a 3000 gph to a 4000 gph pump.
Then, there is the waterfall and stream height to factor in and the term, shut off height, comes into play. Most people believe that a pump rated at 3000 gph will always push that amount of water. But once you subject your pump to higher waterfalls or longer streams, it will push less water. Once it hits that shut off height, you are not going to get any more water.
Call us a 877-780-1174 if you have any doubt in the size pump you may need.
Plumbing
Plumbing used with pumps is also an important part of the equation. Using the wrong plumbing can cause friction, hindering the performance of your pump and affecting the power of your waterfall.
We believe that the Flexible PVC is the best for pond projects. It will handle sharp turns and tight corners and also expands and contracts with seasonal changes.
…1.5 inch pipe has a maximum flow rate of 2200 GPH
…2 inch pipe has a maximum fow rate of 4800 GPH
So you can see that pipe selection is very important.
Check Valve
The check valve helps prevent water from back flushing into the pond when the power to your pump is cut. The reason this is important is because you need to keep water in your biological filter so that the beneficial bacteria can continue to grow. The bacteria will die in two hours without water.
Other terms
Discharge – The opening of the pump where the water is expelled.
Impeller – The part of the pump that pushes the water. It generally has fins or blades.
Shaft – The shaft is what spins the impeller. It is generally located inside the motor housing.
Motor – The motor is what drives the pump. The shaft attaches to the motor.
Impeller Housing – This is where the impeller sits and is allowed to spin.
Now you really know how that pump works.
Planning: Sizing Your Pump!
Minimize friction losses by using large diameter pipe. Determine the approximate flow rate that you want, the head height, and the total length of pipe. Consult a Friction Loss Chart to choose the proper diameter pipe.
You can calculate your total head at www.pump-world.com. You will need to know the following:
- The overall height
- The pipe run and diameter of pipe
- The maximum rated flow for the pump
The size of the pump’s suction and discharge ports DO NOT dictate your proper pipe size. Choose a pipe diameter that keeps your friction loss below about 6 feet per 100 feet of pipe. The longer your run of pipe, the more critical it is to minimize your friction loss. Normally, a minimum of 2 inch line is suggested for systems with flow rates from 30 to 50 gallons per minute or 1800 to 3000 gallons per hour.
Use a filtration system that DOES NOT require a lot of pressure. It costs MONEY to create pressure. Biological filters and BIOFALLS® filters work well and require no pressure.
Pipe Diameter Max GPH
1.5 inches……………….. 2,200
2 inch……………………… 4,800
Two 2 inch pipe……….. 9,600
3 inch……………………..10,500
Remember to consider the width of your stream when it enters the pond. You will need 1500 to 2000 GPH for each foot of stream when it comes into the pond.
NEVER run a pump dry. This will damage the seal and impeller. They are designed to pump water, not air. Insure the pump is submerged in water before you turn it on, and be sure it does not out-pump the supply.
If your pump is producing too much flow, you can reduce the flow by partially closing a valve (Ball valve) on the discharge line near its outlet (NEVER RESTRICT THE INLET). Also never restrict more than a quarter turn.
If more flow is required than a single pump can produce, use two or more pumps. This also offers the benefits of being able to vary the flow rates; this can often save a substantial amount of electricity compared to using one very large pump.
Choose a pump that can give you the required flows at the lowest possible AMP draw.
If you have any further questions, please send to info@aquascapes.com
Aquascapes.com
877 780-1174
FALL SEASON!! TIME TO WINTERIZE YOUR FEATURE
Don’t forget to read over the information about Winterizing your feature on our POND TIPS.
The Pond’s Ecosystem
What is an ecosystem?
An ecosystem encompasses all the parts of a living environment, including the plants and animals, AND the non-living components, such as water, air and the sun’s energy. A pond’s ecosystem begins with the water as the base. Everything found above the base is completely dependent, either directly or indirectly, on water.
Biological filters work to create an ecosystem by using bacteria to break down pond wastes, converting them into harmless particles that will be used as aquatic plant fertilizers. Housed inside the biological filter are from one to three filter mats. The filter mats will aid in the building of a bacteria colony. To add additional media, we recommend that you install several sets the BioBalls inside this unit. Again depending on the size of the biological filter you will need from one to four sets. Both of these types of media will allow the bacteria colony to grow and mature.
In the past, people have used the Lava Rocks in mesh bags on top of these mats. We have found, in our research that the lava rocks will eventually clog and recommend they be replaced every two years. These rocks are also heavy and cumbersome to remove and clean. BioBalls are easier to handle and will hold more good bacteria. To guarantee that you have seeded the bacteria into the filter media in the Biofalls, it is important to use the beneficial bacteria on the start up of your system in the spring and continue to use on a regular basis throughout the growing season.
The primary goal of a biological filter is to reduce the level of nitrogen compounds in the water in order to maintain the balance of the pond and limit algae and pathogenic growth. Water quality can be threatened by natural ground water run off, decaying plant particles and too many fish. Uncontrolled algae growth can have serious consequences for the entire pond apart from the unpleasant appearance.
The IonGen™ is an electronic clarifier for ponds and Pondless features. By clicking on the product you will be brought to the product and you can read the description. This product saves the cost of using algaecides. This product is now registered with EPA as a product that will eliminate string algae. However, you still have to use some type of bacteria during the growing season to keep a pond water clear. The IonGen™ saves you time and money!
The biological filter is also the source of your waterfall and/or stream. Besides being the source of the good bacteria colony, it also works for you by making it easier to build a great waterfall. Remember to order your bacteria in the spring so you are ready for the growth season. Go here to look at the various types of bacteria:
How does the biological filtration work?
The water is pumped through the biological filter unit, through the filter media and microscopic bacteria located in this media go to work scrubbing the pond clean of green water. Lava Rock or BioBalls are located in this unit. By combining both mechanical and biological filtration, the Ecosystem does the maintenance for you, reducing your work and increasing your enjoyment.
Mechanical Filter called the Skimmer
The purpose of this filter is to skim the water and deposit the surface debris into a basket or net for easy maintenance. It also protects the pump with a filter mat located either in front of or on top of the pump thus cleaning the water before it is drawn into the pump. The debris net or basket needs to be emptied regularly. Note: The weir door on the Signature Series is a separate part and does not come with the basket.
Weir Doors can be ordered but you need to know which skimmer and the size of the weir opening. Call 877 780-1174 if you have questions.
Other Necessary Parts to the EcoSystem
▪ Pump and Plumbing – Recirculation of a closed water feature is essential to add oxygen to the water for fish and bacteria. It keeps it fresh and allows gasses to escape. You want to circulate the volume of water in your feature approximately every hour. The pump supplies the water to the biological filter which in turn spills over into the waterfall.
▪ Rocks and Gravel – The most under used element in a pond ecosystem is rock and gravel. Rocks are instrumental in protecting your liner from harmful ultraviolet rays as well as helping to prevent hydrostatic bubbling. Rocks and gravel throughout the bottom also provide the perfect areas for bacteria to colonize thereby keeping water clearer. Do you ever see an aquarium without gravel on the bottom? Cover the liner completely with rocks and gravel. Never use more than 2 to 3 inches of gravel on flat areas.
▪ Plants, Fish and Bacteria– Plants absorb the nutrients from the water as fertilizer. The bacteria in your colony will eat the excess nutrients that the plants haven’t absorbed and if these excess nutrients are not absorbed, they might feed green water. That’s why plants are very important to the ecosystem. Plants provide beauty and a nature look to your pond while the bacteria will help remove ammonia, nitrates and other minerals from the water and converting them to useful nutrients. Fish provide some balance the equation but you must not overstock your pond. Overstocking is the number one cause of excess algae. Adding bacteria on a regular basis, is one of the best things you can do for your pond to enhance the quality of your pond water.
The calculation for amount fish in a pond is: length x width of pond = square feet and that number is the inches of mature fish your pond can support. A 10 x 10 pond supports 100 inches of fish. Don’t forget that if you are a new pond owner, the fish will multiply and you may end up with more fish that you should have in order to have a balanced ecosystem.
Filter efficiency Facts
1. Circulation requirements:
Ponds with KOI – re-circulate total pond volume at least once per hour. Also, consider adding an additional aerator at the bottom of the pond.
2. Volume of pond
Average width x average length x average dept x 7.5 = volume of water in gallons.
3. Fish stocking guidelines (bio-load capacity)
For every square foot of pond surface you can support one inch of mature fish.
4. When you use a biological filter and a skimmer filter and have adequate aeration, we don’t normally recommend testing the water unless you have an excess of fish and have not used the four basic ecosystem requirements which is rocks, fish, plants, and aeration. If your pond has a heavy fish load, you may want to test your water for ammonia.
Clarity of water does not always mean quality. To monitor your fish environment especially if you have more fish than the ratio, you may want to test periodically:
…Ammonia
…Nitrate
…pH
…Oxygen
…Temperature
Ammonia – a reading of more than 0.25 ppm will put your fish into stress; make immediate water change of 33% and than re-test ammonia level. If too high, make another 33% water change. Adding bacteria twice weekly or at least once a week will help reduce ammonia load. When doing water exchanges don’t forget to add the pond Detoxifier to the water.
pH – should range between 7.2 and 7.6. When you test the pH, run the test at the same time of day in the a.m. as pH fluctuates during the day. High pH is not necessarily dangerous unless the ammonia count is also high.
Temperature – ideal range is between 72 and 78 degrees. Less or greater can reduce biological activity. Over 80 to 85 degree water could be harmful on your fish.
5. Aquatic plants should be used and added in your pond for nitrate absorption; examples include water lilies, bog plants and water hyacinth placed in the BIOFALLS® filter and streams. See the charts on Planting Your Pond.
Happy pondering,
Aquascapes.com
877 780-1174
