Most pet specialty stores carry flake, granulated and pellet food for goldfish, bettas and tropical fish. By expanding fish food to include frozen food and specialized reef food and supplements, pet retailers can stand out from their competition and become a shopping destination for aquarium hobbyists.
Frozen fish foods contain a variety of ingredients, including shrimp, insects and small organisms like daphnia. They come in small cubes that can be dropped into the tank or thawed prior to feeding. As the cubes melt, food is distributed to hungry fish. The main benefit of frozen fish food is that it retains more of its natural nutrients when compared to commercial and freeze-dried food. Plus, frozen food may keep fish healthier by giving them more energy and bringing out more vibrant colors in their scales.
While some hobbyists drop frozen cubes into their tanks directly, others recommend thawing the cubes first for no more than 30 minutes. The easiest way to do this is to place the cube in a cup of tank water for about 10 minutes, then dump the contents into the tank. If a whole cube is too much for one feeding, chop the cube into smaller portions and then thaw only the amount to be used.
Frozen food cannot be left sitting out on a tank stand or cabinet for easy access. It also is higher priced than flake food, so be prepared to explain the advantages of frozen fish food to hobbyists and know which frozen food is best for each fish species.
Food for Reefs
Each type of reef-tank inhabitant needs specific food and nutritional supplements. Common mistakes are feeding coral reefs the same as fish and feeding coral reefs at the wrong time of day. Some corals only extend their feeding tentacles at night.
For inverts, aquariums must strictly maintain temperature, pH and salinity. Clams and stony corals also need calcium and other minerals or trace elements added to their environment to grow and remain healthy. Some organisms rely on the zooxanthellae embedded in their tissues to produce energy from strong lighting. Some corals require or benefit from supplemental feedings of plankton or meaty foods, in addition to the nutrition obtained from their symbionts.
Many frozen foods are good for reef invertebrates if they are the proper nutritional profile and the correct size. While brine shrimp may work for some, they may be too large for other creatures. A mix of cyclops, rotifers, oyster eggs or other suitable saltwater foods may work, depending on the size of the food. A mixture of these tiny foods and a small quantity of a tiny frozen food, like cyclops, will suit a variety of inverts.
Salt mixes contain many nutrients, but they deplete between water changes and any creature with a calcareous skeleton will use them up when building upon its pre-existing skeleton. Some invertebrates simply cannot survive and grow without supplemental nutrients, especially calcium.