Who eats ricordea and zoo's

[nlreefguy]

a freshwater dip of the affected colonies/rocks might help. For one, it might flush out any hidden predators and two, it is a good treatment for any bacterial diseases that the zoos might have. I had a colony of zoos that was doing very poorly and never really opening and disappearing slowly one by one. A single freshwater dip for around a minute and now they're really on the rebound. Just my own experience, but another idea for you.