Any idea what this is....

[Joe Batt]

I have this purple colour fluff moss like growth in my tank. It started off in a small patch and now seems to be all over the place on the rocks.

Any ideas?

 

[XNavyDiver]

It looks like Gracilaria.

 

[Susan Edwards]

agree. It's a macro algae

 

[Joe Batt]

It whatever type of algae it actually is it seems to like my nutrients. 5ppm ish No3 and 0.003 ish Po4.

 

[Big G]

Could be Gelidium, Red Wiry Turf Algae
Turbo snails will take care of this stuff.