Daphnia

Also known as water flea larvae, these are an excellent food for your goldfish. However, goldfish should be fed this type of food in moderation, since too much of this type of food may act as a laxative and cause serious digestive problems in your fish. Moderation is the key to everything. Daphnia are easily gotten from your local pet shop in small quantities, or it is also possible to culture them at home:

1. Fill ajar with an inch of topsoil. Tamp it down, but don't pack it hard. Some experts like to include manure, and some like to include baker's yeast as well.

2. Carefully pour in some water. Fill the jar until it is three quarters full.

3. Place the jar in the sun for a week. Wait for a good growth of algae. If there is not a good amount of algae, wait another week.

4. Add the Daphnia culture and wait ten to fourteen days.

And there you go, Daphnia! Never take more than one fifth of the culture, as this may keep the culture from recovering. You must feed the culture, and remember to continue to add brewer's yeast or manure during that time, several times a week. This culture will only last two to three weeks, but will provide at least two to three feedings a week for your goldfish.