'Dusty' mould growing on live rock.

[cuffit]

Hi
I set up my first marine tank 3 months ago and now have 3 hermits, two clowns and some live rock. at the weekend I bought some small pieces of live and after a few days there is something growing on it that looks like a greyish green dusty type mould. it was disturbed by a crab and it scattered like dust.
Has anyone got any idea what this could be please
Many thanks.

 

[spoonman]

pictures will help identify.

 

[cuffit]

Sorry, photo attached. the 'growth' is around and above the mushrooms on the centre piece of rock.
Thanks.

 

[spoonman]

Looks like cyano to me. But I am no expert. Perhaps others will chime in.

 

[Flreefer]

Looks like cyano to me. But I am no expert. Perhaps others will chime in.

+1. Looks like Cyano to me too!

 

[Sniperhank]

That is def cyano.

 

[AquaRick]

Looks like Cyano or turf algae. If it comes off with a finger tip it's cyano. If it's stuck really good on the rock, then turf algae.

Either way, you can lower your feeding schedule/amount and siphon it off with a good scrub.

 

[Elitehunter1]

I must be looking at something different but Ive not seen cyano like that. Do you have good water movement?

 

[cuffit]

yes, I have good water movement. I have searched the internet for pics of cyano and have not come across any like this. It doesnt just come off with fingertips, it acts like a dust or powder.

 

[Elitehunter1]

I'd say it's diatris . Cyano is obvious when you see it

 

[Thartsockpg]

Looks like detritus above the left mushroom and then cyano above the right one. There could be a link to it. Cyano feeds of of detritus and other nutrients. You may need to get some nassarius snails they eat detritus.

 

[Elitehunter1]

Detritus*

http://en.m.wikipedia.org/wiki/Detritus

There is your definition

 

[54seaweed]

blowing off your rock with a turkey baster will help , when doing water changes it dislodges any crud you have building on rock