What has started growing on my rockwork?

[Just John]

My tank is 9 months old and I just noticed this grey stuff starting to grow in patches on the rock. What is it?




Picture below is on a shell

 

[vetteguy53081]

Little ones are spirobid worms- clustered but harmless.
Larger ones are vermetid snails and need to be removed at very base- breaking tube wont help

 

[Just John]

Little ones are spirobid worms- clustered but harmless.
Larger ones are vermetid snails and need to be removed at very base- breaking tube wont help

Thanks, but I mean the grey stuff that looks like grey paint on the shell and an oval grey patch on the rock.
But also, where do you see the vermetid snails?

 

[vetteguy53081]

Thanks, but I mean the grey stuff that looks like grey paint on the shell and an oval grey patch on the rock.
But also, where do you see the vermetid snails?

The larger tubes above the purple coloration in tubes appear to be.
The greyish stuff looks like chrysophytes or mulm and will need to be manually scrubbed off preferably outside the tank in a bucket of tank water with a firm toothbrush