| Maybe you are in the planning stages for creating | | | | pond example, I would recommend a 3,000 gph |
| your Koi pond, or it is already set to hold water. | | | | pump. |
| Now it's time to decide on which circulation | | | | Submersible or External Pump? Submersible |
| equipment to buy. Suddenly you are faced with a | | | | pumps are fine for smaller volume ponds. They |
| dizzying array of pump and filter choices! Don't | | | | are underwater, out of sight, and quiet. They are |
| feel overwhelmed! Asking a few relevant | | | | also less expensive than the external pumps. To |
| questions and applying some guidelines can help | | | | clean a submersible pump, you haul it out of the |
| you select the right equipment for your pond's | | | | pond with the hose(s) still attached. An external |
| needs. | | | | pump still has an intake (in the pond), but an |
| Circulation Requirements: Assuming you will have | | | | occasional cleaning of that intake is easier than a |
| some kind of fish present, it is generally accepted | | | | submersible. |
| that the entire pond should be circulated at least | | | | The main advantage of the external pumps is |
| once every two hours. It is even better to do | | | | that they are much more efficient. Look at the |
| this every hour, particularly if you have many fish. | | | | amperage that the pump draws; it relates directly |
| For a 2500-gallon pond, you will want a pump that | | | | to your electric bill. A 4000 gph submersible pump |
| moves 1250-2500 gph (gallons per hour). If you | | | | may use 10 amps, while a 4000 gph external |
| plan to have a waterfall more than a few feet | | | | pump may draw less than 3 amps. That's a huge |
| high, extra energy (and gph) will be required. See | | | | difference, especially over time. |
| the pump's gph rating with head (height). | | | | Generally speaking, a submersible pump up to |
| What is the Pond's Volume? You can already see | | | | 3000 gph is a good choice. When you get to |
| why it is critical to know your pond's volume. It | | | | 4000 gph and much above that, the external |
| determines the pump gph capacity you will need. | | | | pump is clearly a better choice because of its |
| To calculate the approximate volume, apply the | | | | efficiency. |
| following rules. | | | | Biological Filter: This part is really quite easy. The |
| For a square or rectangular pond: (Width in feet) | | | | filters are clearly rated for gph capacity, and now |
| X (Length in feet) X (Average depth in feet) = | | | | you can simply match that up with your pond's |
| Volume in cubic feet. | | | | requirements and the pump you have chosen. |
| For a round pond: (Radius, or half-diameter in | | | | Most good filters combine mechanical filtration with |
| feet) X (Radius, or half-diameter in feet) X (3.14) | | | | biological filtration. The biological filtration is an |
| X (Average depth in feet) = Volume in cubic feet. | | | | absolute must with fish. Definitely select one with |
| Break your pond up into several sections if it has | | | | an easy backwash feature! There are various |
| an irregular shape. Once you have the volume in | | | | media choices, and bead filters are quite popular |
| cubic feet, multiply by 7.5 to find the gallons of | | | | now. |
| water. This is because 1 cubic foot of volume will | | | | You will need to measure how much flexible hose |
| hold 7.5 gallons of water. | | | | is required to connect your equipment and run |
| Example: A rectangular pond - | | | | down into the pond and up to a waterfall; allow |
| (16 ft long) X (8 ft wide) X (3 ft deep avg) X (7.5 | | | | extra. Ask your dealer if you are unsure about |
| gal/cu ft) = 2,880 gallons. | | | | which diameter hose to use with your pump. |
| Circulating the pond every 2 hours requires a | | | | Those are the basic issues you will need to |
| pump rated at around 1,500 gph. Hourly circulation | | | | consider in choosing the right circulation equipment |
| dictates around 3,000 gph. Remember that a | | | | for your pond. Now you should be able to enjoy |
| waterfall raises the requirement, and so does a | | | | your healthy fish! |
| large fish population, or lots of sunlight. For this | | | | |