Start by rinsing a handful of moss. Inspect it for sea debris, sand, and other defects. When it is cleaned and ready, place the moss into enough water to cover it and soak for 4-24 hours at room temperature. Rinse the moss and change out the water every 4-6 hours. The sea moss should become translucent, soft, and double in size. When this happens, drain and rinse one more time.