When the last koi slipped into the pond in October, it felt like the end of a long journey but really, it was just the beginning.
A koi pond doesn’t stop needing attention once it looks pretty. If anything, this is where the real responsibility starts.
As the seasons shifted and the French air turned crisp, our focus moved from construction to care: keeping the water healthy, supporting the koi as temperatures dropped, and making sure the pond could settle into winter safely.
Keeping Pond Water Healthy
Clear water isn’t just about looks it’s a sign that the pond’s biological system is working as it should. Even after cycling, regular checks are essential. We test the water routinely, keeping an eye on ammonia, nitrites, and nitrates, especially during seasonal changes when ponds can be a little unpredictable.
Leaves were our biggest challenge in autumn. Falling debris may look romantic on the surface, but once it sinks and decomposes, it can upset water quality. Our little pond is under a huge Sycamore tree so as unsightly as i think it to be we needed a simple net and did frequent skimming which made a huge difference, and it quickly became part of our weekly routine.
Feeding Koi as Temperatures Drop
Koi metabolism slows as water temperatures fall, so feeding needs to change with the season. As autumn progressed, we reduced feeding gradually, switching to easily digestible food designed for cooler water. When temperatures dropped further, feeding stopped altogether something that that felt worrying at first, but is completely natural and far kinder to their digestive systems.
Watching the koi become less active was a reminder to trust biology over instinct. Healthy koi know how to rest when winter arrives. They were often huddled under some arching rocks together at the bottom.
Preparing the Pond for Winter
Winter pond care is mostly about stability. We made sure the pump and filtration were running efficiently and that water movement was gentle rather than disruptive. The goal isn’t warmth it’s oxygenation and preventing stagnant areas.
We also left parts of the pond undisturbed. That layer of calm, deeper water gives koi a place to settle and conserve energy until spring returns. We had an episode of -10 temperatures which left a thick layer of ice on the surface, the oxygen bubble pump kept one end clear with the constant movement of the bubbles so we weren't too concerned, We also laid some polystyrene sheets over to help with insulation.
Looking Ahead to Spring: Plants and Lighting
While winter is about maintenance, spring is where the dreaming starts again. We’re already planning to add more marginal plants to soften the edges of the pond and create natural shade. Aquatic plants don’t just look beautiful they help balance the ecosystem and give koi places to explore and feel secure.
Lighting is also on the list. Subtle, warm lighting around the pond will extend the evenings spent outside and highlight the water without disturbing the fish. Nothing dramatic just enough to make the space feel calm and inviting. We already have a few solar powered spot lights which look beautiful already and have survived the winter.
More Than Just a Garden Feature
This pond has become one of the focal points in our little garden, with plans for a rockery and a little seating area its a sign of really settling here and making this our home. It’s where mornings start slowly, coffee in hand, watching ripples move across the surface. It’s where we pause in the evenings, listening to water instead of renovation noise.
Caring for koi isn’t flashy or fast. It’s about observation, patience, and respect for the rhythms of nature values that feel more important than ever in this new chapter of our lives.