What Is a Koi Pond?
(And Why It’s Not the Same as a Water Garden Ecosystem Pond)
A koi pond can best be described as a swimming pool for koi or a large, purpose-built tank designed specifically for raising healthy koi. It is very different from a water garden pond, which is primarily designed as a decorative landscape feature.
Water garden ecosystem ponds are designed to look natural in the landscape. Koi ponds are designed for the raising of healthy koi in a more formal pool in the landscape.
Understanding this difference is extremely important before building a pond for koi. Many installation contractors that don't understand the difference between the two often build water garden ecosystem ponds for customers that asked for, wanted, and preferred a koi pond. Sadly, many contractors have been sued for installing the wrong kind of pond.
It is of the utmost importance to understand the differences between a water garden ecosystem pond and a koi pond. They are not the same.
Koi Pond vs. Water Garden Pond
Koi Pond:
A true koi pond is engineered for fish health, water quality, and predator prevention, while a water garden pond focuses on plants, rocks, and aesthetics.
Typical features of a true koi pond include:
- Smooth pond bottom (no rocks or gravel)
- Smooth straight-down sides for predator prevention
- No marginal plant shelves
- Nothing in the pond a koi could harm itself upon
- Bottom drains for continuous waste removal
- External filtration systems
- External pumps and aeration systems
Water Garden Ecosystem Pond:
Water garden ponds are designed to look natural in the landscape with boulders, aquatic plants, and rock and gravel.
Typical features of a water garden ecosystem pond include:
- External, non-backwashable biological waterfall filters
- External pond skimmer
- Boulders on all vertical walls
- Aquatic planting shelves stepped down into the pond
- Rock and gravel covered bottoms
- No bottom drain
- Submersible or external pumps
Koi ponds and water garden ecosystem ponds look different, have different filtration systems, and have different aesthetic designs than each other. Water garden ecosystem ponds are not the same as koi ponds.
Many koi clubs across the country explain that a koi pond is not the same as a water garden ecosystem pond. If you are unsure, check with your local koi club through the Associated Koi Clubs of America (AKCA.org).
While koi can survive in some water garden ponds for a while, they typically do not provide the healthiest long-term environment for raising big, beautiful koi.
How Koi Ponds Are Designed
Unlike water garden ponds (also known as ecosystem ponds), koi ponds are designed more like swimming pools integrated into the landscape.
Koi ponds may be built:
- Completely underground
- Partially above ground
- Fully above ground
They are typically constructed using concrete, concrete block, or structural framing that retains the surrounding soil while a liner, concrete, or polyurea coating holds the water.
Most koi ponds are 3-4 feet deep at a minimum, though many serious koi keepers prefer 5-6 feet or deeper. Greater depth helps protect fish from predators and allows koi to grow larger and healthier.
Koi ponds may include a waterfall, but in many cases waterfalls are not used as part of the filtration system.
Koi Pond Filtration and Water Quality
High-quality koi ponds rely upon external filtration systems designed for easy maintenance and excellent water clarity.
Our Ultimate Koi Ponds use our advanced filtration components such as:
- HydroBead™ Vortex backwashable filters for biological and micro filtration
- HydroClean™ fish-safe, dry-hands serviceable pond skimmers for surface debris removal
- Bottom drains for continuous sunken debris removal
- HydroSieve™ bottom drain pre-filters for mechanical filtration
Oxygen is supplied through an external aeration system, while water circulation is powered by external pumps. Because these systems are located outside the pond, no high-voltage electrical equipment sits in the water.
Some systems can also incorporate Bubble-Less™ aeration technology, allowing crystal-clear viewing of the koi without surface bubbles.
Are Koi Ponds Landscape Features?
Unlike water garden ponds, koi ponds are not primarily landscape features. Instead, they function more like formal aquatic structures, similar to swimming pools designed specifically for fish.
Landscaping can still be incorporated around the koi pond, but the koi pond itself remains optimized for fish health and water quality rather than aquatic plant displays.
Koi Pond Maintenance
One of the advantages of a properly designed koi pond is simple maintenance.
Typical koi pond routine maintenance includes:
- Empty the HydroClean™ pond skimmer weekly
- Empty the HydroSieve™ bottom drain pre-filter weekly
- Backwash the HydroBead™ Vortex koi pond filter monthly
Bottom drains and skimmers continuously remove debris, preventing the buildup of waste that would otherwise require draining and cleaning the pond.
During filter backwashing, some pond water is replaced with fresh water through an automatic water fill valve inside the HydroClean™ pond skimmer, helping maintain ideal water conditions for koi. Backwashing the filter creates small water changes each time the filter is backwashed.
Without waterfalls, koi ponds are also quiet and peaceful, allowing owners to enjoy watching their koi fish glide calmy through crystal clear water.
Where Can You Install a Koi Pond?
Koi ponds can be installed in many types of outdoor spaces, but several factors should be considered:
- Adequate yard space for proper pond size
- Good visibility from patios or viewing areas
- Level ground for easier construction
- Avoiding heavily shaded locations
With thoughtful placement, a koi pond can become a beautiful centerpiece of an outdoor living area.
Can Other Fish Live in a Koi Pond?
Koi ponds can support other compatible fish species, such as goldfish, but not all pond fish are suitable companions.
Before introducing new fish, research their compatibility with koi and consider how they may affect pond maintenance and filtration requirements.
How to Start Your First Koi Pond
The first step in building a koi pond is careful planning.
Most importantly, remember that a koi pond is not the same as a water garden pond. Many pond kits marketed as "koi ponds" are actually designed for water garden ponds.
To start your koi pond project:
- Choose the right location
- Decide on the pond size and depth
- Calculate the total water volume
- Select the proper size filtration system
- Construct the pond structure and plumbing.
Only after the pond is fully built and the filtration system is operating should you introduce koi fish into their new habitat.
A properly designed koi pond provides the safest, healthiest environment for raising koi, allowing these beautiful fish - often called "living jewels" to grow large, vibrant, and strong.
This screenshot is from Aquascape's own website. They make the claim that "koi ponds, also called water gardens ....". This is flat out a false statement. We know of several contractors that have been sued for installing a water garden pond for their customers that wanted a koi pond. A koi pond is nothing like a water garden pond. Yes, you can have koi in a water garden pond, but a water garden pond is not a koi pond or the healthiest choice for raising koi. If you are unsure, contact a local koi club in your area and ask them: "Is a koi pond the same as a water garden pond?". Or: "Is an Aquascape type water garden ecosystem pond the same as a koi pond?". They will tell you that they are not the same - they are completely different types of ponds.
A koi pond can have waterfalls, but in most cases, the waterfalls are not part of the filtration system like those found in Water Garden Ponds, Hybrid Ponds™ or CrossOver Ponds™.
A Koi Pond is not a "landscape" item like Water Garden Ponds, Hybrid Ponds™, or CrossOver Ponds™, but more of a pool or large fish tank specifically designed for keeping Koi.
Our Ultimate Koi Pond Kits are biologically and micro filtered with super efficient, easy to clean HydroBead Vortex™ filters, along with HydroClean™ pond skimmers, bottom drains, and HydroSieve™ bottom drain pre-filters performing the mechanical filtering duties.
Oxygen for the Koi Pond is provided by an aeration system, and the water is pumped with an external pump. No high voltage electrical devices are in the water.
The Koi Pond is constructed with either concrete, concrete blocks, or timbers retaining the earth "outside" the pond and have rubber liner, concrete, or polyurea liner holding the water "inside" the pond.
Landscaping can be placed up to and overhanging the Koi Pond. Maintenance of Koi Ponds is very easy. Simply backwash the HydroBead Vortex™ filter at least every 30 days, rinse the HydroClean™ pond skimmer and HydroSieve™ bottom drain pre-filter elements at least every seven days.
A Koi Pond without waterfalls is a quiet, peaceful pond with beautiful Koi gliding about in blissful silence. All the oxygen in the Koi Pond is supplied by the aeration system. The pond can be lit at night with underwater lighting so the pond owner can view the beautiful Koi at night.
The bottom drain and pond skimmer constantly remove waste and debris from the pond, so the pond doesn't have to be drained for cleaning like typical Aquascape water garden ponds.
Nitrates are removed from the water during the backwash cycles. As pond water is used to clean and rinse the HydroBead™ Vortex filters, new water is replaced in the pond by an automatic water fill valve inside the HydroClean™ pond skimmer.
The water in the Koi Pond is circulated with an external pump, and the aeration system supplies the oxygen. Both units are external and can be placed anywhere outside and away from the pond. This makes for a clean and formal look to the Koi Pond as the filtration units can be placed far away from the pond and out of view.
Koi Ponds are constructed for the sole purpose of raising and keeping koi. They are the ideal pond style for those that want the best and safest pond available for their beloved koi.
The depths of the Koi Pond allow the koi to grow large and strong. The filtration system is external, so it can be easily increased in size as the koi grow in size or numbers. Koi truly are the "Swimming Jewels". The Koi Pond is the safest environment to keep these jewels.
