External vs. Submersible Pumps. Which One Should You Use?

For many people, it's never been a question of whether to use asubmersible pump vs. an external pump because most people havesmaller ponds and are used to just using a submersible pump. They're easy to install, and are pretty reliable - so why evenconsider an external pump?

There are a couple of reasons...

But before we go into that, let's briefly talk about the benefitsof submersible pumps first. For obvious reasons, a submersiblepump is named as such because it is designed to be placed in thepond, and submerged under the water.

These are the easiest of all pumps to install, just drop them inthe water and plug them in - and you're ready to do. Of course,you might have some quick plumbing to do, attaching a hose to thewaterfall or to a submersible filter (another article entirely),but other than that - that's pretty much all there is to it.

Submersible pumps range in size or gallons per hour, from 50 GPHall the way up to 50,000 gallons per hour, but for most ponds -pumps anywhere from 350 GPH to 4000 GPH will do just fine...

So why might you also consider an external pump instead?

Here are a couple reasons. First, external pumps can much moreenergy efficient. Now, a typical swimming pool or spa pump won'tusually fall into this category - so be careful not to compareapples to oranges! Pool pumps can also be huge energy hogs, soalways check the amps to compare different pumps together. Anything over 10 amps will draw a significant amount of $$ out ofyour pocket every month in electrical costs.

The external pumps that we are talking about are designedspecifically for ponds and water gardens, and are engineered forenergy efficiency. I'm not sure why those folks in the swimmingpool and spa industry haven't figured out how to this yet, butI'm sure they'll catch on sooner or later.

I'm inclined to think the average pond owner is a bit moreintelligent than the average pool owner. Why else would someonechoose a pool over a pond? Unless of course you have both, but atany rate - let's just assume that we're talking about externalpond pumps here.

For comparison, a typical 4000 GPH (gallons per hour) submersiblepond pump will typically draw anywhere from 10 amps all the wayup to 15 amps, depending on the brand. This can really burn ahole in your wallet (or pocketbook) on a monthly basis, and insome parts of the country will run you $50 - $70 in energy costs.

In contrast, a comparatively rated external pond pump like theWilliam Lim Wave I External Pump(https://www.macarthurwatergardens.com/Pumps/wave_pump_for_ponds.htm)is rated at 4380 GPH at 3.47 feet of head, and only draws 2.3amps - that's 3/4 less energy consumption than the submersiblepumps.

When you start getting into larger ponds, 1000 gallons up to20,000 and above - it's usually a good idea to look into thesemore energy efficient pumps. For example, the 3/4 HP Dragon pump(https://www.macarthurwatergardens.com/Pumps/dragon_pumps.html)will move 7,770 GPH at almost 5 feet of head (and under pressure)and only burn 6.2 amps.

External pumps are almost always better for using withpressurized external filters as well, as submersible pumps arenot designed to handle all the back pressure. Other benefits ofusing an external pump include:

-> Easy to clean without getting your hands messy

-> Come with a removable leaf trap which clog less often

-> Easy to hook up to bottom drains or surface skimmers

-> Generally last longer, and easier to repair / replace parts

So that's it, more than enough information for you to make aneducated choice.

Just to recap:

For smaller ponds, and for simple installation and daily use,submersible pumps are probably your best option. For largerponds, 1000 gallons and above, it may be worth looking into anexternal pump for your needs. Although they cost a little moreon the front end, the energy savings alone can often more thanoffset this increase in cost during the first year of use alone.

**************************************************
Brett Fogle is the owner of MacArthur Water Gardens and several
other pond-related websites includingMacArthurWatergardens.com
and Pond-Filters-Online.com. He also publishes a free monthly
newsletter called PondStuff! with a reader circulation of over
9,000. To sign up for the free newsletter and receive our FREE
'New Pond Owners Guide' visit MacArthur Water Gardens today!
**************************************************