Ponds 101 Chapter 7
Pump Location & Configuration
Circulation is essential to keep ponds from stagnating. The rule of thumb for backyard ponds is to turn over the full volume every hour, so you would want to recirculate a 1200 gallon pond at a rate of 1200 Gallons Per Hour (GPH). Continuous circulation is definitely recommended, especially overnight when the weather is warm. You might suppose that fish need less oxygen at night because they’re less active, but other factors outweigh any metabolic drop in activity. First off, water tends to hold the heat of the day for a couple of hours after sunset, and warmer water actually holds less oxygen than cooler water. Breezes that help to cool the water and mix in oxygen tend to die down at night. Finally, oxygen levels drop significantly when the sun goes down in well-planted ponds, because plants absorb oxygen overnight and exhale carbon dioxide, so no turning the pump off at night. You’ll want a pump that’s rated for continuous duty, that clogs infrequently and costs the least to operate, and you’ll need to decide where you’re going to put it, either outside, inside or at the edge of the pond.
External Pumps mounted outside the pond, usually above water level, are the type used also for swimming pools. They are very popular for Koi ponds since they are readily accessible for cleaning and maintenance, connect easily to bottom drains and can be very efficient, but they’re tricky to plumb. The intake side has to be perfectly sealed or the pumps will lose prime, and they usually need to be hidden so that the sight and sound of them doesn’t detract from the pond. Submersible pumps, on the other hand, don’t need any intake plumbing, are quiet and the water they are submerged in helps hide them. Submersibles that sit directly in the pond, sucking up sludge, typically require more time and effort to maintain than externals, since they have to be removed from the pond for cleaning and maintenance, which can also be pretty messy. In the search for the simplest installation, lowest maintenance and least visibility, the pond skimmer has become the most popular choice for the pump. Pumps located in skimmers tend to last longer for a couple of good reasons. They only have to deal with clean water, aggressively pre-filtered by the skimmer’s basket, pad, brushes or net, so they tend to clog less and rarely jam, so they overheat less, reducing premature failure. “Clean water” pumps usually cost less to operate than their beefier “Solids-Handling” counterparts, often significantly reducing operating costs. pumps in skimmers also tend to get more attention and preventative maintenance, i.e. regular cleaning, since they are far more accessible at the edge of the pond inside the skimmer, instead of stuck in the muck at the bottom of the pond, yanked up by the cord (ouch!) every so often when they jam with gunk. For now let’s look at the pond skimmer as an ideal location for the pump, housing and protecting the pump at the water’s edge, where it’s easy to maintain. We’ll discuss the different kinds of pumps and how they function in The College of Pumps.
Using spray paint to make visible lines for water level.
Circulation is essential to keep ponds from stagnating. The rule of thumb for backyard ponds is to turn over the full volume every hour, so you would want to recirculate a 1200 gallon pond at a rate of 1200 Gallons Per Hour (GPH). Continuous circulation is definitely recommended, especially overnight when the weather is warm. You might suppose that fish need less oxygen at night because they’re less active, but other factors outweigh any metabolic drop in activity. First off, water tends to hold the heat of the day for a couple of hours after sunset, and warmer water actually holds less oxygen than cooler water. Breezes that help to cool the water and mix in oxygen tend to die down at night. Finally, oxygen levels drop significantly when the sun goes down in well-planted ponds, because plants absorb oxygen overnight and exhale carbon dioxide, so no turning the pump off at night. You’ll want a pump that’s rated for continuous duty, that clogs infrequently and costs the least to operate, and you’ll need to decide where you’re going to put it, either outside, inside or at the edge of the pond.
External Pumps mounted outside the pond, usually above water level, are the type used also for swimming pools. They are very popular for Koi ponds since they are readily accessible for cleaning and maintenance, connect easily to bottom drains and can be very efficient, but they’re tricky to plumb. The intake side has to be perfectly sealed or the pumps will lose prime, and they usually need to be hidden so that the sight and sound of them doesn’t detract from the pond. Submersible pumps, on the other hand, don’t need any intake plumbing, are quiet and the water they are submerged in helps hide them. Submersibles that sit directly in the pond, sucking up sludge, typically require more time and effort to maintain than externals, since they have to be removed from the pond for cleaning and maintenance, which can also be pretty messy. In the search for the simplest installation, lowest maintenance and least visibility, the pond skimmer has become the most popular choice for the pump. Pumps located in skimmers tend to last longer for a couple of good reasons. They only have to deal with clean water, aggressively pre-filtered by the skimmer’s basket, pad, brushes or net, so they tend to clog less and rarely jam, so they overheat less, reducing premature failure. “Clean water” pumps usually cost less to operate than their beefier “Solids-Handling” counterparts, often significantly reducing operating costs. pumps in skimmers also tend to get more attention and preventative maintenance, i.e. regular cleaning, since they are far more accessible at the edge of the pond inside the skimmer, instead of stuck in the muck at the bottom of the pond, yanked up by the cord (ouch!) every so often when they jam with gunk. For now let’s look at the pond skimmer as an ideal location for the pump, housing and protecting the pump at the water’s edge, where it’s easy to maintain. We’ll discuss the different kinds of pumps and how they function in The College of Pumps.
Using spray paint to make visible lines for water level.
