Keeping Rudd: A Complete Guide for UK Pond Owners

Rudd are a lesser-known but charming addition to any garden pond. These native British fish, with their shimmering silver bodies and distinctive red fins, bring natural beauty and lively movement to your pond. Although they’re often associated with wild ponds and waterways, rudd can adapt well to garden ponds if given the right conditions. Here’s everything you need to know about keeping rudd in your pond.

What Are Rudd?

Rudd (Scardinius erythrophthalmus) are small, shoaling fish commonly found in lakes, rivers, and ponds across the UK. They are:

• Silvery in colour: With a greenish back and silvery sides.
• Red-finned: Their bright red fins make them easy to recognise.
• Active swimmers: They prefer to live in shoals and are constantly on the move.

Rudd are well-suited to natural or wildlife ponds and make an excellent addition to ponds aiming for a more natural, balanced ecosystem.

Pond Requirements for Rudd

Pond Size and Depth

Rudd are not as demanding as koi or sturgeon in terms of pond size:

• Minimum pond size: Around 1,000 litres (220 gallons) for a small shoal, though more space is always better.
• Depth: At least 60 cm (24 inches), but 1 metre (3 feet) is ideal for stable temperatures and to avoid winter freezing.

Because rudd are shoaling fish, always keep them in groups of at least five or more.

Filtration and Aeration

While rudd are relatively hardy, good water quality is still essential:

• Filtration: A filter that provides mechanical and biological filtration will help maintain clean, healthy water.
• Aeration: Air stones, waterfalls, or fountains provide oxygen and keep water fresh, particularly important in warmer weather.

Planting and Habitat

Rudd thrive in well-planted ponds:

• Marginal plants: Plants like water iris, marsh marigold, and reeds provide cover and shade.
• Submerged plants: Oxygenators like hornwort and water milfoil help keep water clean and provide shelter for young fish.
• Floating plants: Water lilies and duckweed help to reduce algae by limiting sunlight.

A varied habitat with plenty of plants not only makes your pond more attractive but also provides natural food and hiding places for rudd.

Water Quality

Maintaining good water quality is vital for healthy rudd:

• pH: Should be stable between 7.0 and 8.0.
• Ammonia and nitrite: Must be zero, as they’re toxic to fish.
• Nitrate: Ideally below 40 ppm to discourage algae growth.

Regular water testing (weekly during the summer) and partial water changes (around 10–20% every couple of weeks) will help keep your pond in good condition.

Feeding Rudd

Rudd are omnivores and will happily eat a variety of natural and supplemental foods:

• Natural diet: Insects, small crustaceans, and plant material found in the pond.
• Supplemental feeding: Small pond fish pellets or flakes designed for cold-water fish.
• Live and frozen foods: Occasional treats like bloodworms, daphnia, and mosquito larvae encourage natural foraging behaviour.

Feed rudd once or twice daily in the warmer months, only as much as they can eat within a few minutes. Reduce feeding as temperatures drop in autumn and stop altogether once water temperatures consistently fall below 10°C.

Seasonal Care

Spring

• Restart filtration and check equipment for any damage from winter.
• Resume feeding once temperatures consistently rise above 10°C.
• Perform partial water changes to refresh water after the winter period.

Summer

• Monitor oxygen levels, especially during hot weather.
• Provide shaded areas with plants to reduce temperature fluctuations.
• Watch for algae growth and remove excess manually if needed.

Autumn

• Gradually reduce feeding as temperatures drop.
• Remove fallen leaves to prevent them from decaying and polluting the water.
• Prune pond plants to reduce organic waste build-up.

Winter

• Stop feeding once water temperatures remain below 10°C.
• Keep part of the pond surface ice-free using a pond heater, air stone, or de-icer to allow for gas exchange.
• Avoid disturbing rudd during their winter rest in deeper water.

Health and Common Issues

Rudd are hardy fish, but poor water quality can lead to health issues. Keep an eye out for:

• Lethargy or gasping at the surface: Often indicates low oxygen levels.
• White spot (Ich): Tiny white cysts on fins and body.
• Fungal or bacterial infections: Red streaks, ulcers, or cotton-like growths.

If you notice any of these symptoms, test your water and treat issues promptly, using pond-safe treatments as needed.

Introducing Rudd to Your Pond

When adding new rudd to your pond:

1. Quarantine: If possible, quarantine new fish in a separate tank for a couple of weeks to check for disease.
2. Acclimatise: Float the bag in the pond for 15–20 minutes to equalise temperatures, then gradually add pond water before releasing them.
3. Add in groups: Introduce rudd in small groups to avoid sudden imbalances in your pond’s ecosystem.

Supporting a Balanced Pond Ecosystem

Rudd are well-suited to natural or wildlife-style ponds:

• Natural algae control: Rudd eat small invertebrates and can help keep insect populations in check.
• Peaceful: They mix well with other peaceful pond fish like goldfish and tench.
• Encourage biodiversity: A pond that mimics a natural environment supports local wildlife like frogs, dragonflies, and newts.

Conclusion

Rudd are a lovely, lively addition to any garden pond, bringing a touch of native British beauty and natural balance. With a well-planned pond, good water quality, and a varied diet, your rudd will thrive and become a key part of your garden’s ecosystem.