Purple algae?

[Scoted]

My tank is 8 months old and I have purple algae growing on my rocks. It started like polka dots and than covered the rocks. I used dry rocks to start the tank and I'm wondering if this is a form of Cyanobacteria? It's not overly thick and is not on the sand bed. I have started some GFO in a reactor. Thanks for the id.

 

[ericarenee]

the lights are so blue its hard to tell .is this solid hard growth that covers the surface of the rock or can you just brush it off easily?

if its the first its Coraline algae Very good..

 

[Scoted]

Just hit it with a scrub brush and it didn't come off. I don't have any on my plastic or powerheads though. And it's growing on areas of heavy light exposure.

 

[cloak]

At eight months is probably Coralline algae. This usually does start off as small spots here and there.

 

[Scoted]

Also it's color is more of a dull purple.

 

[heathlindner25]

comes in many different colors

 

[ericarenee]

Just hit it with a scrub brush and it didn't come off. I don't have any on my plastic or powerheads though. And it's growing on areas of heavy light exposure.

Sounds most def like coraline . This is a Very good thing . well in my opinion...

Just curious
what salt mix do you use ?
How big is your tank?
How often do you do water changes?
what lights do you have?

You do not have to answer just wondering. That looks like quite Great Growth from dry rock with no coraline to what it looks like in your tank...

Thanks Erica Renee

 

[Scoted]

Thanks everyone!
I use red sea coral pro salt.
My tanks is a 60 cube with a 75 sump in the basement. Approx 100 gallons water volume.
I change 20 gallons every week in a half to two weeks.
Light is a Radion xr15w pro.
Some of the rock is fiji LR from my old tank which was in the basement for 10 years(seriously) from my old 30 gallon tank. it was in the dark with a powerhead for 7 or so and than just in funky saltwater for 3 more. i dried it out and than mixed it with dry rock.

 

[Scoted]

This is how it started. The pics a little fuzzy but you can see enough.