Purple coralline algae or something else?

[bones6966]

As per title.

 

 

[reefer_evo5]

doesn't look like coralline are you able to blow it off with a turkey baster or something if so definitely not coralline. Maybe cyanobacteria from the looks of it. 

[M. Tournesol]

Can you scratch it or break it? breaking it should give you a calcium like hard chip if it's coralline.

 

[Murphs_Reef]

Absolutely looks like cyanobacteria... Not a real worry though it will clean up a treat and easily. 

It will return daily until you figure out the issue.. for me it's low phosphate.. or rather unbalanced phosphate and nitrates.. I find mine goes away once phosphate is around 0.06 to 0.1 and nitrates are between 5 and 10. 

[bones6966]

45 minutes ago, reefer_evo5 said:

doesn't look like coralline are you able to blow it off with a turkey baster or something if so definitely not coralline. Maybe cyanobacteria from the looks of it. 

It is soft. 

 

48 minutes ago, M. Tournesol said:

Can you scratch it or break it? breaking it should give you a calcium like hard chip if it's coralline.

 

Soft, I assume you are correct.

 

27 minutes ago, Murphych said:

Absolutely looks like cyanobacteria... Not a real worry though it will clean up a treat and easily. 

It will return daily until you figure out the issue.. for me it's low phosphate.. or rather unbalanced phosphate and nitrates.. I find mine goes away once phosphate is around 0.06 to 0.1 and nitrates are between 5 and 10. 

Fair, I will leave it and watch it.. I have had a much healthier tank since I stopped worrying about phosphates. I haven't measured in quite a long time now. Ill watch my nitrates but they haven't been a hue issue since I started target feeding the gang of fish. 

The (what I now assume is cyano) has been there for absolutely ever I just noticed it is slightly bigger and encrusting the rock so was curious. 

 

If it does not pull back on its own I might hit it with a soft brush with the vacuum beside it to catch it all. If it is not harmful, I really don't mind the look of it so I'm not out to make war with it.