Though I bet iodine could maybe be hindering it and although the ICP test could also be false, do you really think a low iodine level would be enough to actually kill a birdsnest or monti? To be honest those are pretty hardy corals its quite hard to kill them as long as they have enough light and you are keeping up with water changes.
But like stated above those Zoas did look like they were reaching for light. The lighting penetration and par might be the issue here.
But like stated above those Zoas did look like they were reaching for light. The lighting penetration and par might be the issue here.