Of all the trace elements found in natural sea water, iodine is associated with the widest range of effects. Iodine prevents goitre as an important component of the thyroid hormone. It also is essential for the hardening of the chitinous shell of crustaceans. Coallinaceous red algae deposit iodine in surface structures and gorgoniias deposit it in the axial skeleton. Experiments clearly show that Tropic Marin Pro-Coral Iodine improves the adaptation to light and the colouring of anthozoa, especially of hard corals. Due to ist unstable nature in solution, iodine should be added to marine aquarium on a regular basis. Tropic Marin Pro-Coral Iodine contains iodine in ist most effective form, as elementary I. Tropic Marin Pro-Coral Iod+ Lugols solution for saltwater aquaria+ essential trace element for sea dweller+ improves the adaptation to light and the coloring of anthozoa, especially of hard corals Recommended dosage of Tropic Marin Pro-Coral Iod:Add one drop of Tropic Marin Pro-Coral