Thoroughly rinse the raw sea moss under cold water to remove salt, sand, and debris. Place the sea moss in a large bowl with lime slices and cover with filtered water. Let it soak for 8–12 hours or overnight until it expands and becomes soft and gel-like.(The brand I use for Raw Sea Moss is in the notes below) Drain the soaked sea moss and rinse it one more time.
Add the soaked sea moss to a blender along with 2–3 cups of filtered water. Blend on high speed for 3–5 minutes until smooth and creamy. Adjust water for your preferred consistency (less water = thicker gel).
Pour the gel into an airtight jar or container and refrigerate. It will thicken further as it chills. Sea moss gel keeps for up to 3–4 weeks in the fridge.