Fish Health - Food and Feeding

Health main page


Aeromonas Hydrophila
Ammonia Test Errors
Anchor Worm
Bacterial Additives
Blanket Weed
Carp Pox
Cat Damage
Costia (killer)
Common Myths
(Egg Compaction)

Fat Fish
Fish Louse
Gill Bleeding
Gill Disease
Gill Maggots
Goldfish Ulcers
Mechanical Fish
Mechanical Injury
Microscope page
Milky Skin
Mouth Cancer
My Fish Jumped
Neon Tetra Disease
pH Crash
Post Mortems
Skin Cancer
Swim Bladder
Tonic Salt
Vitamin C
Water Filters
Water Fungus
White Spot

Cold Weather Feeding

At these low temperatures, if your fish show interest in food, try brown bread. Sprinkle (or drizzle as Jamie Oliver would say) with neat orange juice.

Don't bother with these so called winter feeds for koi, they are rubbish. believe it or not it is harder to digest wheat germ etc. than koi summer food - its a money racket. Its just cheap rubbish food sold at high prices.

Sturgeon in these very low temperatures still need food. Use sardines - rinse under tap for a second or two and feed at night - just a small amount will do. By the time koi realises that it's food, the sturgeon will have eaten them. Start back on your sturgeon pellets when temps get around 8-10oC.


Do not feed plain washed lettuce to your koi. It will either lodge in their throats or damage their digestive tract. Koi cannot digest plain lettuce - far better is broccoli top.

There are many types of fish pellets on the market of which 50% are rubbish, 20% are only useable around 20°C so we are only left with 30% that are really meant for Koi.

There also additives and pastes to use with pellets to enhance growth and colour. What damage they do to Koi over long periods is not known. However, 95% of Koi over 28" die of fat degeneration of their internal organs. There are many reasons for this - poor grade food which is corn based is one, an other is high protein levels in their early stages of life, which damages their liver and kidneys but does not show its self until the fish is around 3-6 years of age.

The ingredients listed on the tub or sack mean nothing if they are old stock. Always check the date stamp and buy from suppliers who have a good turn-over of pellets or from your dealer whose small stock levels means they are receiving food from source regularly.

Beware also of shelf life Air-tight tin foil bags or bucket mean nothing, as you will still get vitamin reduction in old food.

NEVER take your main container outside. Always take just a small tub or cup out to your pond and keep the main container sealed tight. Old or damp pellets will do more harm to your fish than parasites.

I don't feed wheat germ to my fish. Why? Because if any food is indigestible in cold weather its wheat germ. You can feed high protein food in the winter. It will not rot inside the fish, just reduce feeding and miss some days. If wild fish stopped feeding on protein when the temperature dropped, they would all die of starvation, as most wild fish feed most of the year - ask any fisherman, and if the latter was true there would not be any wild fish would there.

So to say that all fish change their diet when the temperature drops is rubbish. Animals that eat plant proteins generally use other forms of life to digest it e.g. bacteria and these require a higher temperature in order to help the bacteria to work faster. So in cold weather this is the opposite to what they need, so they just slow their food intake down. Also, wheat germ has got hardly any nutritional value and and as it's far cheaper to produce manufactures push it in there adverts.

Fish sticks these are complete rubbish and should never be feed to Koi. It is now being found that feeding Koi on a pellet only diet can lead to abdominal problems in latter life. The problem is a fat fish cannot lose weight like we do by exercise. They need to be starved and how do you starve one fish in a pond full of other fish.

There are findings that feeding cooked white cabbage to fat fish does help reduce the fat around the liver, however there still much work to done on this by people with more grey matter than me.

A Varied Diet

To get large fish, forget pellets, as they are a staple food only, no matter how high the grade.

Koi need a varied diet which can include prawn, dog biscuit, scramble egg, cooked small hole new potatoes, oranges, brown bread which is very good for Koi (never white) with marmite or honey or soaked in pure orange juice. Also lettuce (blanched), garden peas and beans (blanched) some breakfast cereals (ensure they have a low sugar content), sweet corn, luncheon meat.

Under no circumstances feed trout pellets to Koi or sturgeon, unless you you want to kill them with catarrh of the intestines (dysentery). The pellets pollute the water.

I hope this gives you a insight into feeding - it's a huge topic, so if you would like any more information email or phone.