We don't keep koi, we keep good water!
Pond Design and Setup
Proper pond setup is one of the most critical elements of successfully keeping koi. An improperly designed pond can make maintaining stable, healthy water parameters extremely difficult, if not impossible. The basic layout of the pond has a significant impact on overall water quality.
We typically recommend a circular or oval pond with vertical sides to help deter predators, along with a minimum depth of 3 feet. This deeper section provides a safe area for your koi during the colder winter months. This style of pond also promotes efficient water movement and helps prevent debris from settling on the bottom, provided there is adequate circulation from a properly sized pump.
What we want to avoid is the buildup of waste on the pond floor that never reaches the filtration system. Ensuring all debris is directed toward the filter is essential for maintaining a clean, healthy environment for your koi.
Filtration
Filtration and its proper maintenance are among the most critical components of a pond system for maintaining high water quality and, therefore, healthy koi. There are many types of pond filters available, and if they are correctly sized and routinely serviced, most can perform adequately. However, the old saying “you get what you pay for” often applies.
Canister-style filters are reasonably effective at trapping waste and pollutants, but when it comes to maintaining long-term water quality, many fall short without extensive upkeep—something most pond owners struggle to stay on top of. The “backwash” feature found on the majority of these units removes very little, if any, of the trapped debris. A few models use a lever-style pumping handle that improves cleaning somewhat, but they still do not achieve a thorough clean. To properly service these filters, all media must be removed and rinsed with non-chlorinated water. This process is time-consuming and often leads to neglected maintenance and poor water conditions.
Another option is the bead filter. While significantly more expensive than canister filters, bead filters are easier to maintain and available in much larger sizes suitable for bigger ponds. When serviced at regular intervals, maintenance takes roughly 30 minutes and keeps water quality consistently high. Some manufacturers even demonstrate servicing the filter in a suit and tie—highlighting just how user-friendly they are. Bead filters use a multi-port valve and a powerful blower to agitate the media, loosening debris before it is flushed out through a backwash cycle. Each brand has its own backwash procedure that must be followed to ensure proper cleaning.
One of the most advanced and effective filtration systems available today is the RDF, or Rotational Drum Filter. These units automatically clean themselves using a control panel and a fine mesh screen capable of filtering out extremely small particles. When sensors detect restricted water flow through the screen, the control box engages a motor that rotates the drum while a high-pressure spray rinses waste out through a dedicated discharge port. Because waste never accumulates inside the filter, RDFs provide exceptionally stable water quality. While they are very expensive, they offer unmatched performance. However, caution should be taken when considering low-cost knockoff RDFs, as many of them are unreliable and prone to malfunction.
A final note regarding manufacturer ratings: many filters are advertised as suitable for ponds of a certain gallon capacity. This is misleading. For example, a filter rated for a 1,500-gallon pond may work for a pond with one fish, but certainly not for a pond with one hundred. Stocking levels make a tremendous difference. For this reason, I always recommend purchasing the largest filter your budget allows. After all, you can’t keep the water too clean.
Pond Pumps
Just like filters, there is a wide range of pond pumps available. And once again, the saying “you get what you pay for” generally holds true.
Sizing Your Pump
When selecting a pump for your pond, several important factors come into play. First, consider whether you prefer a pump that sits inside the pond or one that can be plumbed externally. Many submersible pumps can also operate externally, but some pumps are designed strictly for external use.
The size of your pond, the presence of a stream or waterfall, and the overall pond design all influence the appropriate pump choice. We recommend a turnover rate of at least once per hour, though we often utilize pumps capable of turning the pond volume over as many as four times per hour. Adequate water movement ensures that waste and debris are carried to the filtration system for removal. Increased water flow also benefits koi health by encouraging natural exercise that helps maintain strong muscle tone and prevents the development of sagging bellies, which can be both unhealthy and unattractive.
Koi are carp, and carp naturally inhabit rivers where they are accustomed to consistent water flow—not necessarily rapids, but certainly a steady current. On our farm, many ponds have secondary pumps on timers that increase flow during the day and shut off at night, allowing the koi to rest.
Matching Pump Size to Your Filter
Your filter will also influence the pump size you can use. Most filters have an ideal flow rate at which they operate most effectively. A larger filter typically supports higher flow rates, so we always encourage going as large as your system and budget will allow.
Pump Options
There are many high-quality pumps on the market. Long-established brands such as Artesian, Sequence, and FlowFriend are extremely reliable and energy-efficient, though they are external-use only and tend to be expensive.
We have tested nearly every major pump brand for both internal and external applications. About three years ago, we began using a newer style of DC pump, which converts incoming AC power to DC through a controller. These pumps are highly energy-efficient, competitively priced, and offer adjustable flow settings ranging from 50% to 100%. We now operate most of our ponds using these pumps and have seen significant energy savings as a result.
The brand we currently use and sell is Periha, which has proven to be both reliable and very efficient. Their largest 110V model, the 25000L, moves up to 6,600 gallons per hour while consuming only 160 watts.
There are, however, certain situations where these DC pumps may not be the best choice. When mounted externally, they can be more difficult to prime. They also lose flow more quickly than traditional AC pumps when water must be pushed long distances. When used inside the pond, however, their performance is excellent. Nearly all of our units are mounted externally, and although we experience a slight reduction in water movement, the energy savings far outweigh the trade-off.
Domestic Koi or Japanese Imported Koi
Are the Koi we produce Japanese Koi?
Are Our Koi Considered Japanese?
This is a question we hear quite often, and the answer comes down to how koi are classified within the industry. True Japanese koi are bred, hatched, and raised in Japan. Even if a fish comes from pure Japanese bloodlines, once it is spawned and raised here in the United States, it is officially considered a domestic koi.
At Mountain Top Koi, we use high-quality Japanese imports as our breeding stock to preserve exceptional genetics, vibrant coloration, and proper body conformation. These are the same traits that made Japanese koi world-famous, and we are dedicated to maintaining that same level of excellence in our breeding program.
The “Japanese vs. domestic” label is often used as a marketing distinction, which can create the perception that imported koi are inherently superior. In reality, the true quality of a koi comes from its genetics, environment, and the care it receives throughout its life—not simply where it was born. Our goal at Mountain Top Koi is to produce koi that reflect the beauty, health, and standards of Japanese lineage—right here in the U.S
All koi are NOT created equal!
Japanese vs. Domestic Koi: Understanding the Difference
It’s a common misconception that all Japanese koi are superior to all domestic koi. While it’s true that the very best koi in the world come from Japan—and often command prices in the tens or even hundreds of thousands of dollars—this doesn’t mean that every domestic koi is of lesser quality.
Many large-scale farms in the United States focus on producing koi in bulk for resale to water garden and pet stores, where quantity often takes priority over quality. This practice has contributed to the perception that domestic koi are inferior to their Japanese counterparts.
At Mountain Top Koi, we take a different approach. We focus on quality over quantity, using exceptional Japanese bloodlines and carefully selected broodstock to produce koi that meet high standards of color, body shape, and overall balance. Our goal is to raise koi that rival the beauty and refinement of Japanese imports—at a fraction of the price.
Each year, we produce millions of fry and follow a strict selection process to ensure only the best are grown on. We match varieties carefully—Kohaku to Kohaku, Showa to Showa, and so on—to preserve the purity of each line. Throughout the summer, we perform multiple selections, choosing only the koi that show strong potential to develop into beautiful, high-quality fish that our customers can be proud to own.
Why choose Mountain Top Koi for your next koi purchase?
Our Commitment to Quality and Improvement
At Mountain Top Koi, our mission is simple: to produce the healthiest, highest-quality koi possible. What began over 15 years ago as a personal hobby and passion has grown into a lifelong pursuit of excellence. Early on, we learned that breeding koi is far more complex than simply getting them to spawn and raising the fry. Every detail matters — from the genetics of the parent fish and the quality of the water, to the nutrition they receive and even the makeup of the mud in a rearing pond. Each of these factors plays a vital role in the outcome of a spawn.
Through years of trial, error, and refinement, we’ve developed methods that consistently yield strong, vibrant, and healthy koi. Yet, we’re never fully satisfied — every spawning season is an opportunity to improve upon the last. That constant drive for progress is one of the key things that sets Mountain Top Koi apart.
While many farms maintain closed systems to protect their biosecurity, we take a different approach. Each year, we selectively import new, high-quality Japanese koi to strengthen our bloodlines, prevent genetic weakness, and expand the variety of koi we offer. Every new import undergoes an extensive, multi-month quarantine process before being introduced to our existing broodstock. This ensures both the health of our fish and the long-term integrity of our breeding program.
The result of this dedication is koi that reflect years of careful breeding, selection, and passion. When you purchase from Mountain Top Koi, the only challenge you may face is finding enough space in your pond for all the koi you’ll fall in love with.