it took my yellow colony polyps about a month before they started spreading. now i am having an issue keeping them in a controlled space. i've been using kalk paste to keep them in a controlled area so they don't spread out of control.
i second what cj10488 said about additives. i wouldn't add iodine for the same reasons he stated. it can be toxic....especially if you are not testing for iodine. i've also had problems finding a reliable iodine kit. i bought a salifert iodine kit and it just doesn't give accurate results. i think iodine must be something that is very difficult to test for due to salt mixes, foods we add, etc. don't add anything you are not testing for.....if you add too many types of different additives you can throw you tank way out of balance. believe me, i know....that was one of my mistakes when i first set up my tank. i thought since the fish store carried these additives i must need them. well i didn't!

now i only add calcium and alk to my tank and things are simple and in balance and working really well. it's also alot cheaper
