ID OF ALGA

[Icedog]

This alga started appearing on the front glass in my tank about 1-2 months ago. It's green and each colony is very round - see the two colonies indicated in the picture below. I get about 3-5 colonies of this alga every week and clean them off during my weekly water change, but they always come back. Also, they're very crusty and hard to scrape off the glass. Any ideas on what type of alga this might be?

 

[Neoalchemist]

Green calcerous algea, close cousin to coraline algea.
Its good.

 

[Icedog]

Green calcerous algea, close cousin to coraline algea.
Its good.

Thanks for the ID and the quick response! Oh, wow . . .

I do understand that coralline alga is good for the tank, but I assumed that it would be growing on the rock. Is this growth on the glass just one of those things I'll have to deal with? That is, just scrape the colonies off the glass every week? Will it ever go away completely from the glass?

Forgive my ignorance - I'm still learning all of the tricks of this trade, but loving every minute of it!

 

[Neoalchemist]

It will continuously grow and have to be scraped. It shows up right before purple and pink coraline but will persist in areas.

 

[Icedog]

Thanks again! That answers all of my questions!