Minecraft wiki entry for Sea_Pickle_farming, associated text: Farming sea pickles while away from keyboard takes a bit of redstone. First, the player must plant a sea pickle underwater on top of a coral block. A dispenser puts bonemeal on the sea pickle, causing it to multiply to 4 pickles. Then, the block underneath the pickles can be moved, or they are directly broken with a piston. The challenge is that a block update detector cannot be used for this since water spontaneously causes block updates.