Rock turns green?

[Fab The Fish]

Ok so my rock started turning green and it's been about 2 months I have had the tank up, I think the green stuff is coralline algae which I want! So I got excited when a big purple spot showed up in my tank!!! It appeared overnight and by the next day the whole purple spot was gone ! Is this normal and will my green algae turn purple and why did my purple which seemed to be starting disappear.

Thank you

-Fab

 

[Dr. Reef]

Green is most likely algea starting in such a new tank and probably not coralline u are looking for. Also are you measuring cal alk and mag along with Phos and nitrates. Coz all those will play roll in correct respective numbers to sustain coralline along with right spectrum of light and exposure

 

[CrayolaViolence]

Green coralline is usually very pale, almost white in color. It also tends to be thick and look kinda shell like or waxy thick. In my experience it's one of the harder coralline algeas to grow in the home aquarium. I think it has to do with the light. From what I have seen (and where I have seen the green) it's usually deeper in the ocean.

 

[mcgyvr]

More than likely just regular green film algae thats very common in a new tank..

 

[BlackTip]

My tank is 18 months old, I still get green film algae on the rocks. I blow it off with small pump before water changes.

 

[mcgyvr]

My tank is 18 months old, I still get green film algae on the rocks. I blow it off with small pump before water changes.

Sorry to hear that.. You really shouldn't..
Nitrate/phosphate issues?

 

[BlackTip]

Sorry to hear that.. You really shouldn't..
Nitrate/phosphate issues?

Phosphate has been always .04 or less for the past 8 months. I stopped using GFO more than 8 months ago. Nitrate has been always 0 except for the past month. Climbed up from 0 to 4-5 ppm. I reduced feeding, and that seam to help a bit. I only feed twice a day and not all that much.

The algae is green and thin. It blows off easily with small power head.

Is this turf algae?