For these reasons, fish feeds should be purchased frequently, ideally at least once a month and more frequently if possible.

Feeds should be stored in a cool, dry place and should never be kept on hand for more than three months. Refrigeration of dry feeds is not recommended because of the high moisture content of that environment. Freezing is an acceptable way of extending the shelf life, however.

Vitamin C is an essential vitamin for fish, and most species tested are not capable of synthesizing their own. Stabilized (phosphorylated) forms of ascorbic acid are available and are used in many, but not all, fish feeds. Feeds that do not contain stabilized ascorbic acid are not recommended for fish. If assays for ascorbic acid content are to be run it is imperative to know which form the vitamin is in before sending the feed sample to a laboratory.