Feed Box allows a Fish NFT to store feeds up to 50. It does not affect the amount of feed refilled. Feed Box is available for 1,000 TDT (50% Locked, 50% Unlocked) on the Shop page.
Feed Box can also be used for Fish NFTs in virus-infected conditions. TDT will not be earned if the Fish is infected with the virus, but the Feed refilled during that period will store in Feed Box.