How Long Does a Pond Pump Need to Be on Each Day?
A pond pump and a filter are necessary to maintain pond health. A well-maintained pond adds value to a home, and even though a large pond with fish requires more maintenance than a small pond, it is worth the extra effort, providing movement, color and a dramatic landscape element. A pond’s pump should run 24 hours each day to ensure the pond’s water circulates through the filter to keep the water clear.
Pump Function
A pond pump may be submerged in the pond’s water or sit outside the pond, depending on the pump type, but both types work in the same way. The pump uses spinning blades, known as impellers, to pull pond water through a screenlike intake and expel the water through an outlet pipe. Generally, a large pond has an external pump and a smaller pond or water garden has a submersible pump. Any kind of pump requires regular maintenance of its intake filter and screen to prevent clogging.
Pump Size
Before buying a pond pump, calculate your pond’s water capacity to determine the size of pump required to circulate all of the pond’s water through the pump every one to two hours. Formulas can help you determine your pond’s water capacity in gallons from pond measurements taken in feet. The formula for a rectangular pond is length x width x depth x 7.48 = gallons. For a circular pond, the formula is radius x radius x 3.14 x average depth x 7.48 = gallons. The formula for an irregularly shaped pond requires dividing the pond into easier-to-calculate shapes, figuring the water capacity in gallons for each of those shapes and then multiplying the total sum of those gallons by 231 instead of 7.48.
Operating Cost
A pond that has a pump or other electric equipment requires electricity, and so it will increase your monthly electric cost. Some pumps cost less to operate than other pumps. Reduce the cost of pump operation by using a pump that moves the necessary amount of pond water while using the least amount watts; a watt is a measurement of electrical usage. Calculate the cost of operating a pump by using this formula: Divide the watts by 1,000, and then multiply that figure by 24 hours, the number of days per operation and electricity cost. An example is: 300 watts/1000 x 24 hours x 30 days x 0.08 for electricity cost = $17.28 as the cost to run the pump for 30 days.
Other Considerations
Mosquitoes can be a problem when a pond is in the landscape, but mosquitoes lay eggs in only stagnant water. A pump can keep the pond water moving, deterring mosquitoes from laying eggs in the water. Even a small amount of moving water can prevent mosquitoes from laying eggs. So if a pump is not feasible, add a fountain bubbler to keep water moving.
How Many Watts Would a 2.5 HP Pump Use?
A pump helps circulate and filter the water in a pool. A pump’s horsepower determines how quickly the pump can process all the water. The goal is for the pump to sufficiently filter all the water in an 8 to 10 hour period, according to Aquascapes. Depending on the size and volume of your pool, you will need more or less horsepower to filter the water in that ideal time frame. Horsepower can be converted to watts, giving you a guesstimate of what your energy costs might be to run your pump.
Math Conversions
One horsepower is equal to 745.7 watts. When you multiply 745.7 watts by 2.5 hp, you get 1,864.25 watts. Energy costs are calculated in kilowatt-hours, and to get kilowatt-hours, you multiply watts by hours and divide by 1,000. So, if you run your pool pump for 8 hours in one day, 1,864.25 multiplied by 8 and divided by 1,000 equals 14.9 kilowatt-hours. If you run your pump every day for an average of 30 days per month — 30 multiplied by 14.9 — your pump uses 447 kilowatt-hours in a month.
Facts: H2O – Oxygen in your Pond
You know that your pond needs oxygen in the water but do you know how much and how often?
Oxygenation is the process in which oxygen is diffused into the water. This process happens every time your water comes into contact with the air.
If there is no aeration in a pond, the pond cannot exchange gasses at the deeper levels of the pond and can only exchange gases at the water surface and therefore, will support only a few fish. Ponds deeper than 3 feet will benefit from a bottom aerator in the summer, especially if this pond is a koi pond.
A pond needs to absorb oxygen from the air and it also needs to release carbon dioxide and hydrogen sulfide among other gases.
Hydrogen sulfide is one of these gasses that contribute to breaking down organic matter in the bottom of the pond. The pond bottom has less oxygen than the upper layers of a pond.
When you use a biological filter or a fountain or have a stream, you increase the surface that is exposed to the atmosphere. Harmful gasses can be released and oxygen absorbed.
Is something wrong with my fish when they swim up near the waterfall and roll around in the area?
They are getting oxygen created by the bubbles that generated from the waterfall. This is a fix of higher concentrated oxygenated water.
But on the other hand, if you see your fish “gasping for air” at the water’s surface, “they may be lacking enough oxygen in the water”.
What is the role of plants in the oxygen supply to a pond?
Plants should only cover 50% to 60% of your pond surface. If you have too many plants in a pond and the entire surface is covered you will have very little gas exchange unless you have a very large waterfall and/or stream.
Adding submergible oxygenator plants (such as Anacharis or Hornwort) will add oxygen to the water but while they add oxygen during the daylight, they use up the available oxygen at night the same as other plant life in the pond.
Anacharis is an important submergible plant as it uses up nutrients that starve out the algae. Go to planning your pond to see how many Anacharis plants you need for your size pond.
Rarely does one overstock with oxygenators, but if in the morning you see your fish gasping for air, you may need to remove some of your oxygenators. The oxygenators may be taking too much of the oxygen over night. Removing too many at once is not good either since it may upset the balance of your pond. Remember plants remove the oxygen in the pond at night.
Oxygenators are the utility player in the roster of pond plants as they serve as a natural filter, a hiding place for fish, an algal combatant and they look good while doing it all.
Suggested oxygenators: Anacharis, Hornwort, Cabomba, Parrot Feather, and Mosiac Plant. The submerged ones create the most oxygen.
How do fish enter into the oxygen issue?
There is a limit to the number of fish that you can keep in a pond before you compromise the quality of your pond water. When you exceed this number you start having problems with water quality and fish health. Usually it is recommended to have 1 inch of fish (mature size) per 1 square foot of surface area of your pond. Stock lighter in the beginning and gradually add more fish but never stocking more than 1.5 inches to 1 square foot.
How does the temperature of my pond water affect the oxygen supply?
The hotter the water the less oxygen it can hold, therefore cold water holds much more oxygen. Using a small bubbler or aerator adds enough oxygen for most size ponds in the winter. Fish do not require a lot of oxygen in the winter because of hibernation. Warm water has a low capacity for holding oxygen, while cooler water can hold gigantic amounts of oxygen. Warm water and increased activity go hand and hand, and that increased activity means fish require more oxygen.
Stressed fish often begin to develop diseases. If you live in a very warm climate, you might consider stocking with more tropical fish like the swordtail or tilapia rather than coldwater fish.
Also if you live in a hot zone, it is sometimes advised to do a partial water exchange when you water temperature gets high (over 80 degrees). Don’t forget to dechlorinator or use a water conditioner for any city water. You can also add an additional bubbler that will increase the oxygen level of your pond.
To keep your oxygen flow at a healthy level, you need to keep a watch on the amount of plants and fish in your pond. Plants should cover no more than 60% of your pond. Remember fish will produce more fish so start with fewer fish in the beginning.
If you ever have to shut down your pump for any length of time, aeration is vitally important for the life of your fish. In hot weather, your fish could be in danger with a pump failure. It is always wise to keep a bubbler or aerator on hand just in case. In very hot climates where the water is very warm, fish can die within a few hours without oxygen.AquaForceTM Solids Handling Pump. This pump has a three year warranty and can be used for winterizing or in hot weather to provide additional oxygen to the fish. Comes in two sizes 1000 GPH, and 2000 GPH. And best of all it cost between $3.65 to $8.03 to run.
A back up pump is always a good thing to have.
A good recommendation is the
Call customer service at 877 780-1174 if you have questions.
Happy Pondering,
Aquascapes.com
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.
