One head sick?

[Mizzy]

Hello.

Do you have some tips whats going on? What is happening to this head? I post water info later. 2 heads are fine. Other corals too.just this one have some problem.

Thx for tips

 

[vetteguy53081]

Head is receded. Common causes:

too much flow on that side
Inadequate lighting
High phosphate
High nitrate
Salinity elevated
Temperature too warm
Low calcium
Hi alkalinity

 

[Mizzy]

Any idea about that black parts of that head? The 2 of em have nice pink "tentacles" and the one black. Can be coz of that its hiden?