Is this cyano algea

Mth281 · Dec 21, 2017

So this particular piece of liverock has a dark red paint like layer. I'm pretty sure it's coralline. But I have a lot of water movement in my tank and it moves some sand around. My live rock is getting sand on it and the sand is now turning red. It only the sand on this rock, there is no other growth like this in my tank. It's my oldest live rock and is probably around 5 years old. This photo makes it look fuzzy but it's actually just the sand on the rock, I tried wiping it off and besides the sand I had to chip off the red layer. Does coralline algae grow on sand that in contact with it? Also there's a fine air stone next to this rock so there are some bubbles stuck to the rock. They stick to my hand if I put it on this side of the tank.

sfin52 · Dec 21, 2017

What’s your water parameters including phosphates and nitrates.

Mth281 · Dec 21, 2017

I'm not sure of my phosphates, I just got this tank from a friend. It has tap water but I've slowly been swapping out ro water. I've done 20 gallons out of a 55 gallon. I don't have a way to test phosphates yet but the city list them as .17 ppm. My parameters are at zero and nitrates are just under 5ppm. Temp is 79-80 degrees and salinity is 1.024-1.025.

Mth281 · Dec 21, 2017

Here's a good photo. You can see how it's almost growing around the sand. You can see the individual grains and it's not really leaving a mat on the rock, it's live it's covering the individual grains on sand.

Mth281 · Dec 21, 2017

So I just got home and syphoned off the sand, I had to scrape it to get the sand of and it all sank. No floating algae or anything. So I'm pretty sure in coralline growing on my sand!

Dsnakes · Dec 21, 2017

Mth281 said:
Here's a good photo. You can see how it's almost growing around the sand. You can see the individual grains and it's not really leaving a mat on the rock, it's live it's covering the individual grains on sand.

Are those bubbles trapped in it? Hard to tell from the photo. The top portion of rock.

sfin52 · Dec 21, 2017

Yes they look like bubbles and not trapped but produced. I’m leaning toward dino. You thinking the same thing @Dsnakes

Mth281 · Dec 21, 2017

Dsnakes said:
Are those bubbles trapped in it? Hard to tell from the photo. The top portion of rock.

Doesn't appear to be, I have and air stone right next to this rock and a lot of water movement so bubbles are all over. I just stuck my hand next to the rock and took a photo, took half a second to cover my hands In bubbles.

Dsnakes · Dec 21, 2017

sfin52 said:
Yes they look like bubbles and not trapped but produced. I’m leaning toward dino. You thinking the same thing @Dsnakes

Yeah looks more that way. Not much of a cyano look to me

Mth281 · Dec 21, 2017

Also my tanks ph is 8.1 and alk is just under the 10. I looked up the Dino algae and this has no stingy parts, which is part of the reason I was thinking it's not an algae. My tank does has some diatoms in the corner but it's a different color. Here's the stuff I scraped off in a cup with water.