What could this be

[Hempknight]

So I bought 2 live rocks but all the dry rock that I started with is turning green not sure if this is a good or bad thing also in my live rock you can see grey spots at the top what is it and how do I get it to go purple

 

[Flippers4pups]

Beginning stages of coraline algae. You have coraline on other rocks, matter of time before the new rocks turn purple. Takes time. Keep your alkalinity, calcium and magnesium in line and it will grow.

 

[Hempknight]

Is there anything I can do to keep the green away or just let it do its thing I'm gonna be checking calcium levels later today

 

[Flippers4pups]

Coraline will start out sometimes green, as with dry rock, and turn purple in time. It's a natural progression of this type of algae. There's nothing you can do to stop the color of it.

 

[saltyfilmfolks]

Coraline will start out sometimes green, as with dry rock, and turn purple in time. It's a natural progression of this type of algae. There's nothing you can do to stop the color of it.

Yup.

And try not to sweat the small stuff. I've had some of my rock for many years. Itll change a lot. One day you may say, hey, why is that white?

 

[Susan Edwards]

Mine started out green. Added a few new rocks and they too are starting green even with the coraline coming in.