Monthly News - December
- World of Nishikigoi
- 11 minutes ago
- 9 min read
#December Update
Well, the year draws to a close, and the December Update marks the last of 2025. What a year. There's been a lot going on in the hobby and industry over the past twelve months, and it's inspired so many articles and random thought trains that it might take me some time to get it all out. But I suppose that's no bad thing. I thought I'd drop you an update, with news from sponsors and what's been happening at HQ - so, without further ado...
#New Sponsors
Firstly, I’d like to take a moment to introduce a number of new sponsors who have joined World of Nishikigoi. Supporting the publication through sponsorship allows me to continue producing in-depth, printed work without compromising on standards - and I’m very pleased to welcome the following partners to our already-awesome team.
Niwa Nishikigoi is a UK-based koi dealer that has recently opened its doors. Long-term koi hobbyist Craig Hooton is the owner and man in charge, and the company is focused on offering carefully selected Japanese koi, sourced with long-term development in mind. Don’t expect a one-stop shop, but do expect hands-on customer care, thoughtful service and healthy, well-cared-for koi.
Craig has been busy buying new autumn harvest stock, which are currently undergoing a strict QT protocol. However, some of them have already made it to the website with the option to reserve for winter holding. Check out the link - after all, Christmas money is there to be spent!
VIVANI needs little introduction. They are a huge company based in the Netherlands, specialising in high-quality animal nutrition and care products. They show so much support for the koi hobby and the show scene in the UK, and I’m thrilled to have them on board.
Their range of products reflects a contemporary approach to koi keeping by focusing on solutions that integrate with modern pond environments. VIVANI highlights how innovation can complement (rather than replace) the traditional principles that underpin successful koi care.
Vivani also offers services to trade members who wish to have their own branded products - food for thought if you want to stand out from the crowd.
The Koi Page (and Koi Wish), run by Siebe Van Tilburg, started life as a social media platform that gained traction quickly. Nowadays, most serious koi collectors and buyers know Siebe as a strong presence on the global koi stage. He’s a koi dealer based in the Netherlands, supplying hobbyists and dealers, priding himself on finding the best koi for his clients. He even offers a special raising and conditioning service at his facility.
He’s absolutely koi crazy this man, and often travels to the UK to support our shows, and he's always up for talking koi. I’m delighted to have his brand on board. Follow him on socials to keep in the loop.
#Winter Feeding
Winter feeding is one of those subjects in koi keeping that never quite settles, and EVERYONE has an opinion. Some insist that feeding below 10°C is dangerous, while others point to wild carp grazing through winter as proof that koi should never be starved. As with most things in the hobby, the truth is more nuanced...
Much of the modern discussion around winter feeding builds on long-standing observations made by people such as Syd Mitchell, who challenged rigid temperature rules and encouraged koi keepers to think more deeply about koi physiology rather than relying on fear-based advice. If you heat your pond and know what you’re doing, much of this may not apply. However, if you run at ambient temperatures, it’s worth reading on.
Hibernation. Firstly, koi do not hibernate in the way mammals do. What we see during winter is a state known as torpor. Because koi are cold-blooded, their body temperature mirrors that of the surrounding water. As the pond cools, every biological process slows. Heart rate decreases, respiration becomes shallow, digestion slows to a crawl, and immune responses weaken. It's a normal, energy-saving adaptation that allows koi to survive winter conditions. Koi will instinctively reduce their activity and often settle near the bottom of the pond, which is inherited from their carp ancestors, who learned that deeper water offers greater thermal stability during cold periods. While the same doesn’t fully apply to our recirculated koi ponds, the koi don’t know that, and the behaviour remains deeply ingrained.
Metabolism. Water temperature governs koi metabolism more than any other factor. Carp metabolism follows what is known as the Q10 temperature coefficient, meaning that for roughly every 10°C drop in temperature, metabolic activity is reduced by about half, though this can vary with conditions. In practical terms, growth stops, appetite shrinks, and the energy required for daily survival becomes very low. Even so, metabolism never stops entirely. A koi still needs energy for its heart to beat, its gills to function, and its basic cellular processes to continue. You guessed it, that energy has to come from somewhere.
The Wild. In the wild, carp do eat during winter, but not in the way we might imagine. They don’t actively forage or consume significant meals. Instead, they may occasionally ingest soft plant matter, detritus, or organic scraps. These materials are naturally available, easily digested, and eaten only when survival instincts kick in. It works because natural lakes and rivers are vast systems where waste gets diluted, temperature changes are gradual, and food availability is self-regulated. A koi pond, by contrast, is a closed environment where every gram of food added must ultimately be processed by filtration and water changes.
At Home. During winter, koi rely primarily on stored body reserves. Fat deposits are used first, providing a slow and steady source of energy. If food deprivation is extreme and prolonged, muscle protein can also be metabolised. This process is gradual, and healthy koi are well adapted to survive periods with little or no food. In artificial ponds, the real question is not whether koi can survive without food, but whether carefully managed feeding might help maintain condition without introducing unnecessary risk.
Advice. The long-standing advice to stop feeding below around 10°C exists for good reason. As temperatures fall, the enzymes responsible for digestion, particularly those that process protein, become far less efficient. Food remains in the gut for extended periods, increasing the risk of internal decay, bacterial imbalance, and stress on an already suppressed immune system.
Uneaten food presents an equally serious problem. In cold water, decomposition is slow but persistent, allowing waste to accumulate and compromise water quality at a time when koi are least able to cope with stress. It's why comparisons with wild carp must be made carefully; feeding at home is not the same as opportunistic grazing in a natural pond.
Winter feeding is not inherently harmful, but it must be approached with restraint and awareness. When water temperatures are stable in the upper single digits, and koi are clearly active and searching, small feed amounts can be offered safely. Wheatgerm-based foods are well-suited to these conditions because they are low in protein and place minimal demand on the digestive system. The emphasis should never be on temperature alone, but on behaviour. Koi that are resting motionless and uninterested in food should not be fed, regardless of thermometer readings. Conversely, active fish in a well-maintained pond may safely accept a light feed when conditions genuinely allow.
There is also a point at which cold itself becomes the primary concern, regardless of feeding. As temperatures continue to fall and remain consistently low, koi naturally enter deeper torpor. At this stage, feeding offers no real benefit and introduces unnecessary risk. Healthy koi will comfortably overwinter on stored energy reserves, provided water quality remains stable and oxygen exchange is maintained.
Winter Care. Good winter koi care extends far beyond nutrition. Water quality still matters, even when fish are inactive, as ammonia, nitrite, and pH can fluctuate unnoticed. Sudden temperature changes are often more dangerous than the cold itself, making consistent monitoring essential. Ice must never be allowed to completely seal the pond surface, as trapped gases and depleted oxygen can quickly become lethal. Just as critically, koi should not be disturbed during winter, as handling stress combined with a suppressed immune system can lead to serious health issues.
Overall. Koi do not require food to survive winter, nor are they harmed simply because feeding stops. However, if carefully judged under appropriate conditions, minimal feeding can be safe in some ponds. Problems arise not from fasting, but from overfeeding, poor observation, and declining water quality. The most important rule of winter feeding has little to do with ideal numbers. It comes down to understanding your pond, watching your fish, and respecting the limits imposed by cold water. Keep on top of your observational skills, and your koi will emerge in spring healthy, strong, and ready to thrive.
#Koi for Sale
Many dealers have taken delivery of their new autumn harvest koi, which are now undergoing quarantine, I had a sift through and put together some koi that caught my eye for one reason or another. Enlarge the image to see which dealer stocks the koi
- and be quick getting to their websites!
#YouTube Stuff
If you haven't already, check out the latest videos on our YouTube channel. One explores a hobbyist pond and their koi keeping journey, the other is a visit to a koi farm many will be unaware of - Ippinya.
#Wrap Up
A Hobby Built on People
As the year draws to a close, one thing that continues to stand out to me is just how much of this hobby is built on people giving their time. Whether it’s club members organising events, hobbyists opening their ponds to others, or individuals quietly supporting things behind the scenes, koi keeping relies heavily on goodwill.
One of the biggest structural changes towards the end of this year was the dissolution of the British Koi Keepers Society (BKKS) following a members’ vote. For many hobbyists, particularly those not directly connected to the society, this may not feel immediately impactful. However, it will have consequences for how the public-facing side of the hobby operates and develops.
The Judging Standards Committee, for example, has already had to adapt, reorganising its structure and funding, and has recently re-launched under a new name (learn more here: https://koijudges.uk/). UK koi shows previously run as section shows will now need to source their own insurance and licensing, and while this may sound administrative, any added complexity for volunteer-run events can quickly become problematic.
It’s worth reminding ourselves that the UK show scene is not a given. Shows exist because people give up their time, energy, and often their sanity to make them happen. Any extra cost, workload, or headache can become the proverbial straw that breaks the camel’s back. In light of this, 2026 could be a testing year, so if you’re able to lend a hand, do. If not, make the effort to attend shows next year and show your support.
They aren’t perfect, and they’re not for everyone, but they remain one of the most important ways of promoting the hobby, pushing standards, introducing newcomers and keeping enthusiasm alive. Yes, people can watch YouTube (and many do), but seeing a high-quality koi in the flesh, something that catches your eye or sparks your imagination, is what really lights the fire.
A Hobby Shared.
This year has also reminded me of how enjoyable koi keeping can be when it’s shared. Some of the most rewarding moments don’t happen online, but through pond visits, informal chit chat, and time spent with other hobbyists away from screens. There is something grounding about standing by a pond with others, meeting at a koi dealer or a show, talking through fish, exchanging opinions, and occasionally disagreeing - all in good spirit, of course!
So, let’s remember to share the hobby in 2026. Invite people over. Put the phone down. Bowl a fish. Sit by the pond with a coffee or a beer and talk nonsense. Those moments are often where the magic lives, and they’re why most of us fell in love with koi keeping in the first place.
World of Nishikigoi
Over the past year, World of Nishikigoi has continued to grow quietly and steadily. What began as a magazine project has become something many readers now treat as a companion to the hobby, something to return to, rather than something to scroll past and forget.
The response to Volume Eight has been very encouraging so far, and it’s been particularly rewarding to see copies finding their way to collectors around the world. That sense of permanence remains central to what this publication is trying to achieve. If you haven’t got yourself a copy yet, the online shop will be open again very soon:
I want to thank everyone who supports my work - readers, contributors, trade sponsors, and those who take the time to engage with it. Without that support, the publication simply wouldn’t exist. Whatever 2026 brings, keep doing the hobby your way and remember how lucky we all are to be alive and to be keeping them there, koi!
Best Wishes & Happy Koi Keeping,
Liam
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