Krill are very small shrimp, measuring only 2 to 3 inches in length and weighing in at just over a gram. These tiny creatures make up a large percentage of the plankton in the world's oceans, and are the base of the marine food chain. They are also popular food sources for fish tank denizens like fish, crabs and lobsters. Although you can purchase dried krill at a pet store, it may be cheaper, in the long run, to raise your own live krill.
Set up a small fish tank for krill, independent of any fish tank that has fish and other creatures in it. Even if you plan to raise krill as a food source for those creatures, they'll eat the krill before they can breed if they're put in the same tank. Keep the two populations separate to keep krill safe. Equip your krill tank with a pump, filter and saltwater (available at aquarium supply shops) for the krill.
Purchase live krill from a pet shop or retailer and put them in your tank. Don't overcrowd the tank; put about 20 krill in a 10-gallon tank, and depend on them to reproduce. Place live plants around the tank as well, for the krill to eat and live in.
Feed the krill daily with algae pellets, which will sink to the bottom for these small crustaceans. Don't heat their water, as they don't need warm temperatures, but do keep an eye on the water's cleanliness. If the water gets cluttered or dirty, change it out by emptying and replacing 10 per cent of the tank at a time. Female krill lay eggs in the summer, and may lay up to 3,000 eggs per year. Young krill take two to three years to mature, and make good food sources for other animals as long as they're in their larval stage.
Krill can live for up to five years if they're not killed or damaged.