We can't work out how much food - minimum and maximum amounts - you are supposed to feed them. We have a tub of pellets. The shop says it's trial an error most of the time but are there any guidelines, such as an average weight/number of food pellets per fish?
Appreciate it's not an exact science, but any advice would be welcome.
Thanks, R & C Graham

Feeding fish is a double-edged sword. Most experienced fishkeepers will tell you that most fish deaths are caused by over-feeding, not because the fish get too fat but that the amount of uneaten or undigested food leads to water pollution, and other problems.

Goldfish, regardless of variety, have a continuous alimentary tract rather than a stomach and can, theoretically, feed all day. However, when 'surplus-to-requirements' food is available they do take it in and almost at once pass it out the other end undigested.

As you are keeping your fish in an indoor aquarium, your task is made far easier, as you can see what's being eaten or not. In a pond, especially with fast-sinking foods it's a bit harder to gauge what amount to give.

You should aim to feed as much as the fish will eat in around a minute or two - how's that for an exact science? With a family aquarium, and the fact that fish expect you to feed them every time you pass by their tank, you should ensure that everyone in the family knows when the fish have been fed, otherwise the "Well, they looked hungry" syndrome will set in and the tank will be over-fed.

Feed morning and evening is a rough guide to frequency of feeding but it often needs an iron will of self-discipline to deny perhaps just a tiny feed at other times!
Try to vary the diet with different brands of food: flakes, granules, pellets, sticks etc are all fine. You can also feed live foods such as Daphnia, Tubifex and Bloodworm or their frozen equivalents.