Aquavitro Shrimp Exo work as a source of iodine to encourage molting (and mating). Do keep in mind that molting can be fatal if the water condition is not right or if the shrimp is not healthy. Therefore it is not advice to use Shrimp Exo within 2 weeks after introducing new shrimps and it is essential to make sure you have the correct water parameters. Use Aquavitro Shrimp pHa & pHb along with Shrimp GH to create a proper condition for shrimps.