Does any one know what this is..

[The-new-stig]

I have had my reef running for months now with no faults but lately I'm having a purple/red growth around the sand and rocks does any one now why and what can I do to get rid of it...





The red growth





More growth

 

[ccCapt]

It's cyano and it's caused by excessive nutrients in your tank.
What are your water parameters?
Do you use RO/DI water for water changes and top offs?
How often do you do water changes and how much do you change?
To help lessen the amount of nutrients in your tank, feed your fish less, run a high quality carbon and do more frequent water changes.