Settle debate between a friend and I!

[TheReefAddict]

What is on the back arch of this photo?

 

[Utubereefer]

Coralline or cyano

 

[rtparty]

Does it blow off easy?

 

[TheReefAddict]

I’m looking for just gut instincts!

 

[TheReefAddict]

Coralline or cyano

And there lies the debate!

 

[xXBlaznReaperXx]

What is on the back arch of this photo?

If blows away likely cyano and if like firm and on there good a red coraline

 

[TheReefAddict]

You guys are not helping me

 

[exnisstech]

I vote coraline. It doesn't brush or scrape off. The only thing that can get that stuff off of my rocks is an urchin. EDIT: unless it blows off then I lean toward cyano

Close-up

Same rock months later after adding an urchin. Lights out so I used a flashlight

 

[VintageReefer]

It would be very odd that cyano would grow like this, only on that rock, and so well…without being anywhere else

It would be very odd to be coralline due to color, and also, due to it being plating

I could see it being either but it’s unusual to me. My first guess was a form of macro like dragon’s breath

 

[KrisReef]

I’m looking for just gut instincts!

I see a coral banded shrimp and a frogspawn and red cyanobacteria.

I can almost make out a reflection in the image but I will have to go to the lab to isolate that faint image.

 

[daanvb]

Looking at the rock and sand, this is a fairly new set up, I would be surprised if this is coralline. With its silky look my bet is on cyano.

 

[Miami Reef]

Cyano.

 

[Red_Beard]

Looks like cyano to me too. Especially the way it floresces.

 

[fish_collector]

cyano

 

[halfpennyreef]

Tank owner here for some added context. Tank is 2 years old. That arch in the photo has been in the tank since day 1. The white rock in the bottom right was added about 3 months ago. In this video, I start by scraping a different arch that was added about 8 months ago with similar patches of red. Last piece of info I’ll add - in the photo I’ve attached, you’ll see the very first hermit crab added to my new tank 2 years ago. I picked it because of it’s strikingly red shell. Because the loser of this debate has agreed to cover lunch and beers, I don’t want to bias the jury, but please help us settle this once and for all because I’m getting thirsty!

 

[halfpennyreef]

Had to trim videos for file size

 

[TheReefAddict]

I’ll be happy to buy the beers, after a third party inspection!

 

[KrisReef]

The dress is black?

I think an image isn’t going to work to see coralline algae v cyano. The description and red crab explanation say this red is coralline algae, but the image is 98% cyano on my screen.

 

[rtparty]

My worry is it’s a type of red turf algae that will devour everything in its path. If it doesn’t blow off easily, it’s not cyano. That is a VERY important part of the puzzle

 

[gbroadbridge]

What is on the back arch of this photo?

Red Paint.