Fish Ponds in Spring: Koi Fishponds & Life

Page Summary: Im sure you can notice the change in your own general attitude and personal approach to life as Spring arrives. Well your pond fish and its inhabitants also feel like this. Small changes in pond water temperature coincident with longer periods of daylight are the signals that Spring is around the corner. Koi and goldfish will be anticipating a new period of activity and a spawning opportunity. If you prepared your pond for winter in the autumn and if youve kept a close eye on your pond in winter then get ready for excitement and change. As water temperatures rise so will the activity of the koi and goldfish in the pond. Theres going to be babies soon...

Ponds in Spring

When your fishpond reaches the 10 degrees Celsius threshold, your koi and goldfish will become noticeably more active and will also require more food to meet their energy needs. As waste production increases along with rising temperatures and certain opportunistic organisms, the character of your pond in spring will inevitably change. It’s good to take heed of the possible setbacks that can occur during this time:

  • Pathogenic Organisms
  • Certain harmful bacteria, fungi, viruses and parasites will have endured the harsh winter months, albeit in small amounts. During the favourable springtime conditions, they will multiply rapidly, so it’s best to take a proactive approach.

    Examine each koi fish when they begin to come to the surface to feed. Every koi is unique, and each individual fish will have experienced the effects of winter differently – some you will find in good health, while you may find others that have sores, ulcers, fin or tail erosion and even big external parasites attached. Another springtime ailment is koi pox virus, which is the cause of wax-like growths.

Sponsored Products...

Koi Food BradshawsEvery koi keeper buys food. All koi foods are not the same. Bradshaws Koi Food (and winter Wheatgerm) is as good as the best for quality and fantastic value for money in modern sensible koi food packaging.

VirescoVERY IMPORTANT PRODUCT: Make sure that you dont have blanketweed or algae problems this summer. Viresco sold worldwide from UK manufacturer is THE natural string algae solution. Use in conjunction with UVC

Hozelock Pond Vacuum Keep that pond bottom clean with reliable Pond Vacuum

Bradshaws Liner25 year flexible pond liner guarantee

Interpet Koi Pond Test KitTesting pond water can in itself become an intriguing and interesting hobby. Get a reliable test kit however.

To ward off disease during spring, you can make use of a broad-spectrum treatment such as a formalin or malachite green-based solution. These remedies will minimise the density of pathogenic organisms until your kois’ immune systems are fully functional.

The Pond Environment

Fortunately, beneficial bacteria also begin to flourish in warmer temperatures – feeding off the nitrate, ammonia and organic waste from your now active koi and gold fish. In order to keep these good bacteria around in healthy doses, you will need to ensure that they have an adequate food source so that they can reproduce and begin to break down the increasing amount of waste that will now be entering your koi pond in spring.

Your prime task during this time will involve keeping the pond environment balanced. The beneficial bacteria are limited in their ability to process organic waste, so it’s vitally important that you don’t allow an insurmountable quantity of waste to enter the pond. Too much waste will contaminate the pond water and could prove lethal to your koi.

The best solution to this problem is a low protein diet while you nurture the levels of good bacteria. Your koi will digest the low protein diet more effectively, which will consequently lower the level of waste production.

Springtime Maintenance Checklist

  1. Test pond water - nitrate and pH levels are important fishpond health indicators.
  2. Replace UV bulb - your current UV bulb’s output will have weakened significantly since the previous spring, putting your pond at risk of developing green water.
  3. Filter care - clean out any accumulated solid substances. A great tip to enhance filter performance is to borrow some filter extract from someone who runs a heated pond during winter – the autotrophic and heterotrophic bacteria, as well as beneficial micro-organisms, will work their magic in no time.
  4. Extract silt - use a pond vac to remove silt from the pond bottom before koi and goldfish activity churns up the sediment.

What are the Warning Signs?

  1. Disinterested koi - fish that remain on the bottom of the pond and take no interest in food should be bowled and checked for lesions which, if found, should be treated topically.
  2. Rising ammonia and nitrate levels - excessive early feeding will negatively affect an immature springtime filter, so testing and feeding should be done in conjunction with one another to ensure a healthy pond in spring.

How do I Keep my Pond Clear and Sparkling in Spring?

Springtime’s longer days and warmer weather have their benefits, but they also present a unique set of challenges. After enjoying months of beautiful water clarity thanks to cold temperatures and reduced flow rate, you might now find yourself with an algae-laden fishpond in only a few short weeks.

It is vitally important that you act swiftly to counteract the effects of nutrient build up and intensive sunlight combined with the churning action of increased koi activity. The most advantageous time to take preventative measures is when the water temperature is still below 10 degrees Celsius and the fish are not yet active – this will allow a clear view of the pond’s bottom.

It is highly recommended that you make use of a pond-vac, which can be purchased or hired from an aquatic store. Using a pond-vac, you should make a thorough effort to get rid of the silt that has settled on the bottom of the fishpond. Any silt that is left will provide a source of nutrients for algae to flourish, so a scrupulous clean up will certainly be rewarding in the long-run.

The temperature of your pond in spring will continue to rise steadily above 10 degrees Celsius, and this is when the changes in your koi and their environment will become more evident. The sub-10 degrees Celsius temperature, however, should be regarded as a window of opportunity to perform aesthetic and biological maintenance in preparation for the summer months.


On this site we dont pretend to be "Koi Crazy" despite the fact that you will see I refer to koi more often than not.

Make fish pond maintenance easy all year round ... Pond vacs, pond nets tools and protective clothing for cleaning your pond

Fish food and water treatments for pond and fish

Latest Articles

Koi Fishfood and Goldfish Food for Pond Keepers. Fish, Facts & Fiction

Practical Seasonal Koi Pond Care: Koi, Goldfish Pond Keeping for Winter Spring

Overwintering Koi & Fish Ponds: Winter Pond Keeping & Freezing Pond Water

Care of Koi, Goldfish & Pond Fish in Cold Winter. Wheatgerm Koi Food

Koi goldfish pond covers over winter. How to look after pondfish

Sex of Koi. Male Koi & Female Koi Differences. Spawning Brushes for Egg Deposits

Frozen Koi Ponds & Fish Ponds. Ponds Freeze in Winter. Pond Care in Freezing Winter Weather

Koi Pond Heaters. Why Heat a Koi Pond? Koi Fishpond Heating. Is it Necessary?

Want to Heat Your Koi Pond? Fish Pond Heating in UK & Water Temperature Control

How Big do Koi Grow? How Fast do Koi Grow? Koi Growth Factor s and Bunkum

Water Leaks & the Leaking Koi Fish Pond: Help in Finding the Ponds Water Leak

Getting Koi Pond and Koi, or Goldfish Ponds Ready for the Spring

Interpet Koi Pond Test KitWhat the Does pH of Koi Pond Water Mean? Should I measure Pond pH

Pros & Cons of Heating Koi Pond Water for Optimum Koi Pond Conditions

Koi Pond Care: Garden Fish Ponds in Spring

Keeping Koi, Koi Ponds & GoldFish Pond Care. Fish Pond Solutions

Koi Survival. Dissolved Oxygen in your Koi Pond. Aeration & Air blowers

All About Koi Food & Koi Digestion. Koi Food Ingredients

Koi Pond Jewels. Colour of Koi. Japanese Koi names

You buy a house with a koi pond. A koi fish pond? What next?

Koi Ponds: Osmosis and Diffusion. Koi Metabolism Factors

Koi Breeding in Koi Ponds: Breed Koi & Goldfish but not for Money

Blanketweed or String Algae in Koi Ponds. Blanket Weed is Slimy, Floats on Pondwater

Pond Water Temperature Changes: Fish Pond Water Temperature in Autumn

Koi Ponds: How to Reduce Surface Foam on Pond Water Surface

Koi Ponds: Fish Pond Water Temperature Changes in Spring Time

Pond Building: rigid preformed plastic pond or fibreglass ponds

How does the KHV Koi Virus Disease affect my Fishpond and Koi Health?

Breeding Koi. To Make Profits from Breeding Koi is Almost Impossible