Green spots on glass?

[JLVN]

Green little algae spots on the glass
Good or bad ?!
Or what are they exactly?

[leebca]

Is it algae groups, or is it a single organism? Can we get a much closer look? Have you scraped some off? What does it appear like when scraped off (stays together or sort of dissolves)? Are they moving?

[JLVN]

I couldn't get any closer pics (camera on my phone doesn't work very well). I scraped some off and it comes off like scraping dried paint, it stays together doesn't really dissolve. They don't seem to be moving and I there are some purple ones coming in too. I think the purple ones are Coraline algae, is there such thing as green ones? Up close it looks the same as the purple spots on the glass.

[pgsasi]

Looks like algae from the pic..you shld be able to scrap them off easily. dont let them grow....

[JLVN]

Thanks, would it be a type my lawnmower blenny could eat? if so I'll leave some on the back glass.

[pgsasi]

I dont think so....

[leebca]

Coralline algae comes in many different colors, including green. I think this is the mostly likely nature of those spots.

[JLVN]

Thanks for the info, but how could i turn that green into purple or pink colors?

[leebca]

Like the growth of all marine algae, it needs nutrients and lighting. Treat the Coralline algae like you would a reef non-mobile invertebrate and supply proper amount of calcium, alkalinity, and magnesium. HOWEVER these things need to be in the proper balance (not just within their own ranges). The proper balance is given in this post:
What is Water Quality

It takes time and excellent water quality to grow Coralline. Don't both spending money on any additives or products EXCEPT you should be adding micro elements once a month.

[Ninong]

You aren't by any chance asking about the whitish spiral-shaped "spots," are you?

[twisted]

i have a section of my tank i let that stuff hang around on and found that my tangs and lawnmower munch on it through the day. then the areas around it get scraped and they get a nice treat as they anxiously wait for small pieces to come off and they chomp it down. im not saying that to disagree with everyone else, i always thought it was a good thing to have a little. though i think if the stuff is growing out of control it is definitly a nutrient issue

[JLVN]

Huh? What white spiral shaped dots?

[Ninong]

I'm talking about all of those spiral-shaped calcareous polychaete worms that show up on the glass in your picture. Is that what you're asking about?

[JLVN]

I wasn't, but are those something to worry about!?

[Ninong]

I wasn't, but are those something to worry about!?

No, they're harmless.

[JLVN]

Well at least I know what those are too. Thanks for the info!