Rasta Zoas losing coral over half polyp

[islandreefer2]

Has anyone seen zoos do this before I’m worried it will spread to other ones ?

 

[vetteguy53081]

Take a look at your lighting
They utilize zooxanthellae to produce their colors and is generated by light
Too low will do this. Also add iodide to water periodically which they convert to iodine for color and growth