zoas shrinking

Have had a frag of rainbow incinerators and utter chaos grow out over the last year on a rock. Despite near constant growth that has overtaken the rock, some of the RIs have shrunk in size and got brighter. Some others have just shrunk and melted. The UCs have fluctuated in growth, some...

My rainbow incinerators and even my rastas are way smaller than my utter chaos. Anyone have similar experience? Could something else be causing my zoas to shrink up like this? i just started feeding reef roids this week i wonder if itll make a difference Kinda hard to see but the rainbow...