Osmosis experiment

Coda

Recently I am doing the osmosis experiment. But the result didn't turn out well. Following what have been told in the internet, I soaked the potato into the salt water for whole day, but the osmosis effect seems really small.

Anyone have a better sugguestion? I think there have better food/material compare with potato, I am happy if someone willing to list it out.

Note that my water is mix with seasalt, that wont be a problem, right?