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How To Look After Yard Pond Fish: The Ultimate Guide

A catfish out of water that appears to be smiling.

Having fish in a yard pond enhances the beauty and enjoyment of the space dramatically. To get the most pleasure from your yard pond fish, it is essential to care for them correctly. So, what principles and practices do we need to know about yard pond fish care?

Yard pond fish need sufficient food to maintain optimum health and beauty, especially in summer. Submerged plants, microorganisms, filters, and pumps keep pond water clean and oxygenated. Regular pond cleaning and water replacement also prevent the harmful accumulation of organic matter and silt.

Caring for yard pond fish isn’t exceedingly complicated. Nonetheless, it is vital to provide the fish with suitable water conditions and to feed them correctly. This guide aims to give you the knowledge to look after yard pond fish without spending unnecessary time, effort, and money.

Related: How to Look After Goldfish in a Pond: The Ulitmate Guide

Caring For Yard Pond Fish: A Brief Overview

The aesthetic and ecological benefits of yard pond fish depend on the health and well-being of these charming aquatic creatures. Fortunately, it is relatively simple to ensure that yard pond fish have the food and water conditions they need to thrive for years.

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Here are some fundamental principles for yard pond fish care…

Regular Feeding

Feeding is a primary task when looking after yard pond fish. While there might be insects and other wild food sources in the yard, pond fish need regular feeding to provide for their calorific and nutritional needs. The type of food and the regularity of feeding depends on the fish species and population numbers in the pond.

Fish eating fish food out of a hand in the water.
Each fish species have different feeding needs

Appropriate Pond Size

To thrive, fish need a pond of appropriate size. One must consider the size and number of individual fish relative to the pond’s length, depth, and volume. Densely-stocked ponds are more prone to disease outbreaks and they typically require higher levels of maintenance and filtration than ponds that are sparsely stocked.

Proper Pond and Water Care

To keep the fish happy and healthy, it is also crucial to care for the pond itself. Regular monitoring and management of water quality are vital for keeping the pond’s water clean and oxygenated. Filters and pumps are widely used to ensure optimal water conditions and require routine checks and maintenance. 

Ponds with diverse, living ecosystems generally require less mechanized filters and pumps than ponds with a limited number of plant, fish, and microorganism species.

NOTE: Weeding and pruning pond plants and removing plant debris and kinds of excess organic matter are also vital for fish health.  

Adapt With Seasons

Seasonal changes are another significant factor when looking after yard pond fish. Pond fish are less active during the colder winter months (unless you’re in the tropics), so they require less food than in summer. The need for a filter is also reduced or eliminated in winter because cold water has more oxygen than warm water.

Caring For Different Types of Yard Pond Fish

There are dozens of fish species that are suitable for yard ponds. Each type of pond fish has its own feeding and habitat preferences.

Let’s look at some of the most commonly-kept yard pond fish species and how to care for them:


Goldfish are an exceedingly popular pond fish due to their myriad shapes, sizes, and colors. They are also very easy to look after.

Goldfish have a tranquil temperament and live peacefully with other pond fish species. They are not picky eaters and will consume general-purpose meat and plant-based fish foods. This pond goldfish food from Amazon is a great value.

Goldfish are hardy and tolerate a wide range of water conditions. They prefer temperatures between 65F and 85F and handle cold water well. This makes goldfish an excellent choice for ponds that freeze over in winter.

NOTE: While the ideal pH for goldfish is 7.0 to 7.4, they do fine in water with a slightly higher or lower pH range.

Goldfish need reasonably clean water. It is advisable to replace about 10% of pond water every week or two. At least half the pond water surface should be covered by plants to keep the water filtered.

Goldfish need adequate space in the pond, which should have at least 30 gallons of volume per fish. Without enough room, goldfish become stressed and less peaceful pond mates.


Koi are the iconic yard pond fish. Their stunning colors, patterns, and impressive size makes these fish the centerpiece of any pond.

Koi are generally more difficult to care for than other popular pond fish like goldfish. One of the challenges of looking after koi fish is that they need stable water conditions. For instance, water temperatures in the pond should not fluctuate more than 2F in 24 hours to avoid stressing the koi and compromising their health.

Koi thrive in ponds with slow but steady water circulation, which ensures the fish have enough oxygen. As a result, air pumps are necessary to provide koi with adequate levels of oxygen to support their optimum physiological functioning.

Koi have specific feeding requirements. They are omnivorous but need higher than average amounts of carbohydrates in their diet. Koi are also heavy feeders that are liable to eat all the food they’re given. If the koi haven’t finished their food after 1 or 2 minutes, refrain from adding more food until the next feeding session.

NOTE: Sinking foods are also recommended for koi because this prevents them from swallowing oxygen at the surface while feeding.

A white and orang and an orange and black koi fish swimming in a pond.
Koi are beautiful and high-maintenance pond fish

Koi are communal fish that can be kept individually or in large communities, depending on the pond’s length, width, and depth.  Despite their intimidating size, koi also co-exist peacefully with other kinds of pond fish like goldfish (especially comets and shubunkins) and high-fin sharks.

To maintain stable water conditions in the pond, is it essential to check the filter and the temperatures daily. It is also vital to monitor pH and water quality every week to ensure the water in the pond isn’t harming the koi. In addition to routine monitoring, 10 to 25% of the pond’s water must be replaced every 2 to 4 weeks.

NOTE: Koi fish prefer an annual water temperature range of 64F to 75F and a neutral pH.

Due to their size, koi need lots of space. Koi also need a lot of room because they are prone to stress and disease in overcrowded ponds. The recommended pond volume for a young koi fish is 29 gallons, with 5 gallons needed for each additional inch of fish. A total pond volume of 1000 to 1500 gallons is ideal for koi. 


Catfish are one of the easiest yard pond fish to look after. These intriguing fish are from highly dynamic freshwater and coastal aquatic systems, so they tolerate a broad spectrum of pond conditions. Channel catfish are probably the most common catfish kept in yard ponds.

Catfish are nocturnal bottom-dwellers that scavenge for their nutritional and caloric needs. They are not overly selective about the types of food they consume and most pond fish foods are suitable for catfish. Sinking fish foods are best for catfish due to their bottom-dwelling nature. 

Catfish prefer shallow ponds or ponds with ample shallow, gently-sloping sections.  The pond should also have a generous selection of hiding places for these characterful bottom-dwellers.

Catfish are hardy and tolerate a wide diversity of water conditions. Nonetheless, catfish prefer minimal or gentle water circulation in the pond. The optimal temperature range for catfish is 60F to 70F, though they exhibit the fastest growth between 80F and 85F.

Catfish vary from 1 inch to a few feet in length, though most catfish in yard ponds are somewhere between.  These fish can be kept individually or in groups, and they handle crowded conditions better than goldfish and koi. Depending on their size, it is advisable to provide about 30 gallons of pond volume per catfish

NOTE: If catfish start becoming paler in color, this is one of the first signs that pond conditions are not conducive to their health.

Chinese High-Fin Banded Sharks

Chinese high-fin banded sharks are a fascinating kind of pond fish. These toothless pseudo-sharks are low to medium-maintenance creatures that add value to any yard pond.

High-fin sharks are bottom dwellers that feed on a wide variety of meat and plant foods, including:

  • fish pellets
  • krill
  • worms
  • algae

These fish are community-oriented, so it’s ideal to have more than a single individual in a yard pond (if there is sufficient space). High-fin sharks are also docile, so they are congenial to other kinds of yard pond fish.

High-fin sharks grow to a maximum length of about 3 to 4 feet. The average length of juvenile high-fin sharks is around 8 inches, and the fish grow to roughly 20 inches long at three years of age. 

As a result of their size, high-fin sharks need a large amount of space to thrive. It is advisable to provide young high-fin sharks with about 55 gallons of water per fish and at least 125 gallons for each mature individual.

High-fin sharks thrive in water temperatures of 60F to 75F (they become dormant when the water is 55F or colder). It is critical to keep the pond water well-oxygenated.

NOTE: Like other bottom-dwelling fish, high-fin sharks thrive and are happiest in ponds with adequate hiding spots.

Yard Pond Care For Optimal Fish Health

Caring for yard ponds is essential for the health of the fish that live in them. One of the principal aims of pond maintenance is to manage the quality of the water. This is achieved by:

  • cleaning the ponds regularly
  • monitoring the water quality
  • checking the pond equipment
  • adjusting the pond maintenance regime to the seasons

Pond Cleanliness

Yard ponds accumulate organic matter from:

  • plant debris
  • uneaten foods
  • fish feces

As the organic matter decomposes, the oxygen and pH levels in pond water decrease, which increases the fish’s risk of stress and disease. Yard ponds need regular cleaning to manage this build-up of organic materials in yard ponds.

Gloved hands cleaning up plant matter from a pond.
Pond cleaning tasks are critical for pond health

NOTE: Plant management is a central aspect of pond cleanliness.

Weekly or bi-weekly yard pond cleaning tasks include:

  • weeding
  • removing excess algae
  • pruning pond plants

These tasks help prevent anaerobic conditions and the build-up of ammonia in the water. Removing excess plant biomass regularly also keeps the water from being covered by plants (which stops the sun from penetrating beneath the water surface).

In addition to regular plant management, yard ponds need thorough cleaning every few years. Large ponds require a complete cleaning every ten years, while small ponds typically need cleaning every five years. Autumn is the ideal time to give a yard pond a comprehensive cleaning.

A pond can be thoroughly cleaned according to the following steps:

  1. Pump water out of the pond (into a tank or container).
  2. As the level of the water drops, gently transfer fish and submerged plants into a temporary water container.
  3. Remove dead or dying plant debris, making sure to leave the decomposing plant material in a bucket of water or on the pond bank overnight to allow small organisms to return to the pond.
  4. Once the pond is nearly empty, remove the silt layer on the bottom of the pond, and ensure to keep a small portion of the silt aside for later use because it contains beneficial micro-organisms
  5. Scrub the liner on the bottom of the pond thoroughly.
  6. Return the saved silt and about two-thirds to three-quarters of the original pond water back into the pond, together with the silt that was saved.
  7. Add fresh water (preferably rainwater) to finish filling the pond to the appropriate level.
  8. Return the submerged plants.
  9. Return the fish.

Pond water conditions and ecosystems take several months to stabilize after these thorough cleanings which are vital for healthy, long-living, and beautiful pond fish and plants.

Monitoring Water Quality

As highlighted earlier, the quality of yard pond water needs regular monitoring to ensure it is within acceptable parameters to support the health of the fish. Checking the water quality is vital for managing water conditions in yard ponds to identify and address problems quickly and effectively.

The temperature and pH levels of yard pond water should undergo weekly or fortnightly monitoring. The cleanliness of the pond water (measured in parts per million or ppm) also requires routine monitoring to meet the needs of sensitive fish like koi and high-fin sharks.

NOTE: Most hand-held digital thermometers, pH meters, and ppm meters provide acceptably accurate readings to monitor water quality in yard ponds successfully.

Checking and Maintaining Pond Equipment

Yard pond pumps and filters are critical for managing the water quality of yard ponds. Filter and pumps perform the essential functions of removing organic debris and maintaining adequate water circulation and aeration in yard ponds.

NOTE: If pumps and filters malfunction, water quality diminishes, causing stress, disease, and potentially death to the fish living in the pond.

Due to their decisive role in fish health, yard pond pumps and filters require routine checking to ensure they are working. Checking this pond equipment enables early detection of mechanical faults, blockages, and other technical problems that might compromise fish’s health.

Pond Maintenance by the Seasons

To support a vibrant, thriving fish population, pond maintenance regimes must shift with the seasons. The seasonal changes in temperature, rainfall, and sunlight necessitate different approaches to pond maintenance in summer and winter.


Summer is the busiest season for yard pond maintenance. Ponds must be topped-up regularly in summer to replace water because the longer days and increased sun intensity result in increased rates of water evaporation. As noted earlier, rainwater is optimal, though tap water left to stabilize for 24 to 48 hours is also suitable.

The oxygen levels in yard ponds decrease during sweltering, humid summer weather. To break the water’s surface tension and increase aeration in the pond, it is advisable to splash the pond with a hose. Activating bubbling water features is another quick and easy way to introduce more oxygen during hot, muggy summer days.   

Pond plants need regular care in summer because of their rapid growth rate. The plants must be fed appropriate fertilizers to support their increased growth in the hot summer months.

NOTE: It is crucial to prune pond plants in summer to prevent them from over-growing the pond and starving the fish of sunlight and oxygen.


In winter, yard ponds need less maintenance because fish are dormant or inactive at this time of year. Water filters should be on a low setting (or switched off) during winter because the fish move, eat, and defecate less, which means less sediment and organic matter accumulating in the pond.

Ponds that freeze over generally require some form of heating to maintain suitable water temperatures. Most freeze-tolerant yard pond fish will benefit from having one or two holes in the ice to allow gas exchange between the water and ambient air.

A frozen pond with a visible fish swimming below the ice.
Ponds can freeze over in cold climate areas

The shorter days and reduced sun intensity in winter mean less of the sun’s light and warmth reaches the pond. Pruning surrounding vegetation above the pond benefits the pond fish and plants by allowing precious winter sunlight to reach the pond.


Caring for yard pond fish is an exceedingly rewarding endeavor and relatively easy. While some fish species like koi and high-fin sharks require medium to high levels of care, species such as catfish and goldfish are exceptionally hardy and don’t need much attention. 

Nonetheless, every kind of yard pond fish species requires clean, adequately oxygenated water, appropriate feeding, and sufficient space to thrive.