Plate coral losing colour

[Dan7575]

Hi all, when I got this plate coral the light bits were really clean and bright but they are starting to look dirty and dull. I have it on the sand bed and have started getting cyano but on the sand only. Could the dirtiness be algae, if so how can I get it back to it’s best?

 

[Jekyl]

Full parameters and lighting?

 

[JoshO]

Mine started to fade and die when it was getting too much flow, it looked very similar to yours!