This morning I saw that my hard coral colour was changing in a few places to a more green at the base with white tips - original pic atatched (little blurry as it was taken with my cell phone up close). Could this be as a result of insufficient nutrients? I am using Red Sea Coral Grow daily as the only additive here as advised by the LFS. The crab and filter feeders on the corals are doing well - should I be concerned?