Iodide concentrated is a concentrated Lugol solution and as demonstrated has multiple effects:
It is necessary for the shapes of prawns and strengthens the shield of Chitina, it is stored by coral algae, from brown algae and gorgonias and hinders the formation of the goiter in the fish.
It also improves the coloring of corals and allows (in greatest way to hard corals) to adapt to light.
Use and doses: In a high-movement area, pour a drop with a pipette supplied every 200lt of water every day, iodine requirements is proportional to the number of animals in the tank, with very populated aquariums you can increase the dosage (not Pass the 2 drops every 200lt).
If a dose forgot, don't add it to the next day but leave it.

