Coralline Algae, or something more sinister?

[bluecheese]

So while doing my weekly tank maintenance this morning, I noticed this purplish spot on a rock.

I added coralline algae to the tank last week, so it seems a bit too soon for a spot this large to appear.

I don't know if this may be something else, like the start of cyano, or dinos.

Tank has been up and running since August 2, 2021. The lights were installed on January 19, 2022. Not too long after, I had an expected breakout of diatoms. The diatoms appear to be dying off at this point.

Any info would be appreciated.

 

[Lavey29]

Since you went lights off the first 4 or 5 months I don't think that's coraline. You will have an ugly phase now that the lights are on but it should be manageable for you. Keep adding good bacteria like PNS probio and if you have no corals don't run the lights to long. More biodiversity is better.

 

[Lavey29]

Make sure your water parameters are good to make your ugly phase less ugly for you.

 

[Noxsolaris]

Does it scrape off with a fingernail?

 

[bluecheese]

Make sure your water parameters are good to make your ugly phase less ugly for you.

Parameters are good and stable. I test weekly, a day after water change day. Last week's testing showed:

1.025 salinity
8 pH
0 ammonia
0 nitrite
5ppm nitrate
1320ppm Magnesium
430ppm Calcium
9dKH Alkalinity

 

[bluecheese]

Does it scrape off with a fingernail?

I just tried rubbing it with the pipe cleaner tool that came with the bottled coralline algae, and some rubbed off.

 

[Noxsolaris]

I just tried rubbing it with the pipe cleaner tool that came with the bottled coralline algae, and some rubbed off.

Probably not coralline then. Maybe some cyano? @vetteguy53081

 

[bluecheese]

Probably not coralline then. Maybe some cyano? @vetteguy53081

I guess I'll keep a close eye on it. Thanks.

 

[vetteguy53081]

I guess I'll keep a close eye on it. Thanks.

Looks like a prestige of coraline which is low on oxygen and flow to form known as phycoerythrin;
You’re correct it’s not easy to remove as it’s trying to establish itself
Allow more flow to reach it along with light and it should harden

 

[bluecheese]

Looks like a prestige of coraline which is low on oxygen and flow to form known as phycoerythrin;
You’re correct it’s not easy to remove as it’s trying to establish itself
Allow more flow to reach it along with light and it should harden

The area appears to get good flow. I assume if a dot of coralline appeared there, I can expect more to appear in other areas. Is that correct thinking?

 

[vetteguy53081]

The area appears to get good flow. I assume if a dot of coralline appeared there, I can expect more to appear in other areas. Is that correct thinking?

Yes- light-flow -calcium all you want to see to reach that coraline establishment

 

[bluecheese]

Yes- light-flow -calcium all you want to see to reach that coraline establishment

Excellent. Thank you.

 

[Lavey29]

The area appears to get good flow. I assume if a dot of coralline appeared there, I can expect more to appear in other areas. Is that correct thinking?

Typically coralline will appear on your plastic parts first like your powerheads or return pipes. Mine were covered in coralline for months before dots started forming on the rocks.

Your parameters look good how about phosphate?

 

[bluecheese]

Your parameters look good how about phosphate?

Phosphate is around 0.03

 

[Lavey29]

The area appears to get good flow. I assume if a dot of coralline appeared there, I can expect more to appear in other areas. Is that correct thinking?

Typically coralline will appear on your plastic parts first like your powerheads or return pipes. Mine were covered in coralline for months before dots started forming on the rocks.

Your parameters look good how about phosphate?

 

[Dan_P]

So while doing my weekly tank maintenance this morning, I noticed this purplish spot on a rock.

I added coralline algae to the tank last week, so it seems a bit too soon for a spot this large to appear.

I don't know if this may be something else, like the start of cyano, or dinos.

Tank has been up and running since August 2, 2021. The lights were installed on January 19, 2022. Not too long after, I had an expected breakout of diatoms. The diatoms appear to be dying off at this point.

Any info would be appreciated.

Always difficult to identify things under blue light. We will need white. The shape of the stuff does not bode well for coralline though.

 

[bluecheese]

Always difficult to identify things under blue light. We will need white. The shape of the stuff does not bode well for coralline though.

White light:

 

[Dan_P]

White light:

Put me down for cyanobacteria growth. Let me know in month what it really is

I never had much coralline growth until I started dosing ChaetoGro to help my Ulva. Now it is all over everything. My system must have been depleted in some trace element.

 

[bluecheese]

I blasted it with a turkey baster, and it started coming off the rock. Starting to think that this is, indeed, cyano. I may add another powerhead in the right corner to get more flow going there. I'll keep an eye on it, and if it looks like its starting to spread, I'll act accordingly.

 

[bluecheese]

So, the spot hasn’t really spread, and has seemed to become thinner, if that makes sense. I don’t think it’s cyano, but I’m not really sure.