Do make sure you have some good current running in the tank, and a place for the shrimp to perch right in the strong part of the current, so they can feed. They sift food from the water with their 'fans', and if they are trying to pick food off the bottom, they are very hungry indeed, and they won't live long if they must feed that way. They are designed to filter feed.
They like microworms, you can give them fish flakes ground to a fine powder, but they should have live food if at all possible at least twice a week. They have been known to climb out of tanks and go walking if they are not happy, it is something they do by instinct. Full grown males can reach four inches, females maybe a bit more.
Males have a thicker pair of first walking legs, female's walking legs are all the same thickness and you can see that when they are still quite young. As they mature, the males grow a big hook behind the main leg joint on that first pair of legs, females do not.
I also feed mine cultured green water, which I make from lab discs I buy. Home made green water may work too.. though it often contains more euglena than actual algae. I pour a cupful into the tank, shut off the filter and leave the pump running so it will circulate the food for awhile.. about a half hour.
They are lovely shrimp to have, but if not fed well tend not to live too long, sadly. Simply dropping fish food in the tank will not feed them. And the tank should be well established, at least six months old, to have enough microscopic life in the water for them to sift out. They need that too, not just man made food.
Good luck, they are fun to have.
