If your goldfish could speak, what type of food do you think he would ask for as you sprinkle yet another helping of fish flakes into his tank?

Goldfish are omnivores which means they are designed to eat a wide variety of foods, both animal and vegetable. Like us, they thrive on a healthy, well-balanced range of foods. Fish flakes alone can't provide all the variety your fish would like.

So, the next time you visit your local aquarist, why not buy some live food such as brine shrimp or daphnia? Brine shrimps are a great source of protein; daphnia are ideal for helping your goldfish avoid constipation, which is more of a problem for goldfish than you might think.

Replacing one or two meals of fish flakes with live food each week, will improve your fish's digestion, and make feeding times more interesting for your fish - and for you. Before adding live food, switch off the tank filter to prevent the food being filtered before your fish can eat it. Remember to switch the filter on again once your fish have finished feeding.

Goldfish love salad
And the scope for adding variety doesn't end there. Did you know that goldfish enjoy nibbling fresh spinach and lettuce leaves? Any type of lettuce will do, although the Romaine variety is a favourite.

Rinse a leaf in clean water, then cut off small pieces and feed them to your goldfish. Alternatively, you can buy a lettuce leaf holder from your aquarist; it will hold a whole lettuce leaf, and allow your fish to bite pieces off to eat.

The leaves provide your goldfish with important vitamins and minerals they need. They also contain carotenoids - red and yellow plant pigments - which means you could even see improvements in the colouring of your goldfish!

Give them the 'squashed pea' treatment
The next time peas are on the menu for your family, save a few cooked peas for your goldfish. All you need to do is squash each pea slightly and remove the outer skin - the skin is too hard for your fish to digest - and then add one or two peas to your fish tank.

Scientists aren't sure exactly why, but a squashed cooked pea can often help a goldfish that is suffering with swim-bladder disease. The swim-bladder helps a goldfish maintain balance and lets it rise and sink. Swim-bladder disease is often caused by the fish's stomach - which lies next to the swim-bladder - becoming distended and pressing against the swim-bladder.

The squashed pea remedy appears to help by moving food and trapped air out of the fish's stomach, which releases pressure on the swim-bladder.

Cook him some gel food
Gel food is easy to make, and because it can be stored in the freezer, you don't have to cook it every day.

You just need a packet of unflavoured gelatin, a 2.5 oz jar of baby food - strained pea, carrot, green bean or spinach varieties are good - and a cup of water. You also need an empty ice cube tray.

Here's how to make it:

1. Pour 1/4 cup of water into a small saucepan.
2. Add the gelatin and stir over a low heat until the gelatin has completely dissolved.
3. Add the baby food and 3/4 cup of water, and continue to stir until it is thoroughly mixed.
4. When it has a smooth consistency, pour the mixture into an ice cube tray and leave it to cool.
5. Refrigerate the mixture. It will solidify in a few hours.

Goldfish feeding tips

1. Goldfish are greedy feeders. They will eat everything you give them and still manage to look hungry. The golden rule is: only give them small amounts of food once or twice a day. Goldfish are far more likely to become ill from overfeeding than from underfeeding.
2. Uneaten food left at the bottom of the tank will cause water problems for your goldfish. It effectively poisons the water they live in. Remove any food that is uneaten or decaying, and if food continues to be left uneaten, reduce the amount you give your fish.
3. Dried fish flakes have a tendency to swell up inside your goldfish's stomach and can lead to digestion and swim-bladder problems. One way to avoid this is to soak the fish flakes before adding them to your fish tank.

You should introduce new foodstuffs into your goldfish's diet gradually. Replacing one or two meals of fish flakes with live food, vegetables, or gel food each week will help keep your goldfish in top condition for years to come.

Elaine Rushmore is the author of The Goldfish Doctor - a step-by-step guide to the diagnosis, treatment and cure of sick goldfish. www.goldfishdoctor.com