Guide on Feeding Koi in Texas Winter

Winter Feeding:

As the water temperature gets colder, the fish metabolism slows down- they tend to swim slower, stay on the bottom and and do not eat as voraciously as in the summer time. High-protein food is not good for koi health in the winter time. If you put the high protein food in the pond, they will eat some of it, and rest will lead to waste buildup that affects water quality.

Best Practice:

Ideally we need to manage koi diet throughout the year, so the questions really are "what's enough?", "what should be done in the colder weather?", and "are there best practices we can live by?"

The secret to feeding is determined by the water-temperature (not air-temperature). Always keep an eye on the water temperature. When air temperature fluctuates, water temperature also changes, but typically at a much slower rate due to water's high specific heat capacity, meaning it takes significantly more energy to change the temperature of water compared to air; therefore, water-temperature fluctuations lag behind air temperature changes and are generally less extreme.

Note: this is true for temperature increase or decrease

Stop feeding altogether below 50°F. This is a highly controversial topic and you will see all kinds of advice on the Internet and Facebook. I am offering my advice based on my research, experience, "Manual of Koi Health" by Keith Holmes/Tony Pitham, and guidance from Dr Jessie Sanders as described in her book "How to Kill You Koi". The Koi will be totally fine and are not suffering. They will get enough nutrition through their stored fat and by eating small amounts of underwater invertebrates in your well established eco-system.

Use this chart as a guide to feeding frequency in relation to water-temperature...

below 50°F –feeding frequency to 1-3 times a week, or less frequent. If your koi are not coming up to eat, then don’t feed. Also, observe the 5min rule.

50°F – 60°F – every other day or less frequent. If your koi are not coming up to eat, then don’t feed. Also, observe the 5min rule.

60°F – 80°F-  daily, 1ce or 2ce a day

Changing the diet to a wheatgerm based food remains a highly controversial topic. However, this is a personal choice, and not something recommended or required. The logic here is that wheatgerm based foods have lower protein, carbs and fats than typical summer koi food, and therefore hence easier to digest. This is true, however, the fact remains the koi's food intake is dependent on the water temperature and they will effectively stop eating at temperatures below/around 50°F, and it doesn't really matter if the food is wheatgerm based or not.

​​​​In Central and South Texas, one could argue that is never gets cold enough, so if you insist on feeding the fish all year around, or not switch to wheat germ, I suggest:

1. Please follow the general rule of thumb is to not feed put in "excessive food"- that means if there's food left over after 5-ish minutes then you put in too much.

2. Wet the food for about 5mins in a bowl before you put it in the water- this will make it mushy and easier to nibble, and the fish don't swallow hard-solid pieces, thereby making it easier to digest. ​

PS- If you are interested in reading more about the correlation of temperature, food intake and energy please see this scientific publication: ("https://pmc.ncbi.nlm.nih.gov/articles/PMC7678922/?utm_source=chatgpt.com

Conclusion: "Temperature is likely the major physical environmental factors affecting the physiology of fish through effects on overall metabolism and energy balance Temperature determines how much energy fish obtains (through regulation of feeding behavior and food intake), how much of that energy is acquired (through digestion and absorption) and how much of it can be allocated to key processes such as activity, growth (including development in larvae and juveniles), and reproduction. Each species usually has a range of temperatures for which physiological processes are optimized, and any deviation from these optimal temperatures might have dramatic effects on the overall health of fish and their survival."