In a high-speed blender, add the blueberries, sugar and water together. Blend until chunky and not completely smooth. Set aside.
Rinse the blender well. Toss in the lime juice, sugar, and water. Blend on high until the sugar is completely dissolved.
Split the lime mixture into your popsicle moulds. It should be ¾ full. Put the mould into the freezer for about 2-3 hours. We want it slightly frozen, not completely.
When the popsicles are slightly frozen, add the blueberry mixture and top it with with ¼" inch of space at the top. This allow the popsicles to expand in the freezer. Insert the popsicle sticks into the mould.
Freeze for 5 hours or overnight.
To Remove Popsicles: Let the mould stand on the counter for a few minutes. Run the popsicle mould under lukewarm water to help loosen. If you have a silicon mould you can pull and stretch it to release the popsicles.
Place the popsicle mould on a plate surface and wiggle the popsicles out.
Wrap the popsicles in plastic when you place them back into the freezer. This helps prevent them from being exposed to air and moisture and maintains the quality and texture of the popsicles, preventing freezer burn and ice crystal formation.