Cyano or Coralline Algea?

[kadewin]

So over the course of a few months, my rock has started to darken and my sand bed has begun to develop a darker color as well. Is this coralline algae, Cyanobacteria, or something else? (Pardon the dirty glass, I’ll be changing water and scraping the glass tomorrow)

 

[Cory]

It would be easier to tell with white light or your cameras flash

 

[kittenbritches]

Guessing since these photos aren't really well-lit...

The spots on the glass look like they could be coralline (but they could be water spots for all I know). The sand bed looks like diatoms.

 

[kadewin]

Yeah, I run 2 blue+ and 2 Coral+. I’ll try getting rid of the blue and update with new pics

 

[Karen00]

The sand looks like cyano. It looks like my sand bed when I asked the same question about a month ago but white lights will help. Can you blow it off your rocks with a turkey baster? That's what I was told to do. I was told if I can blow it off then it's cyano (which I was able to do). I guess it could be something other than cyano but it's not coralline if you can blow it off the rocks (not sure about the sand bed). I think I read coralline clumps on the sand bed. It doesn't sit on top.

 

[kadewin]

 

[kadewin]

It doesn’t come off rocks, it doesn’t feel slimy either. I don’t like to move my sand bed very often, so I only lightly stir it. Per someone’s advice, I don’t gravel vac anymore.

 

[kadewin]

I have a sneaking suspicion the sand bed is a combination of cyano and coralline, only the center of my tank (where light is most intense and flow is the weakest) has the deeper coloration. The rest of the sand bed has a green/yellow dusting which I think is just cyano. I’m not really sure tho, still learning the ropes of reef keeping.

 

[Cory]

The rocks are corraline algae. The sand could be anything its hard to tell.