Coralline Algae progression question..

Lester Verano · Nov 7, 2019

So I've had my first reef tank now for almost a year. I understand coralline algae growth takes time and patience. I have a grayish purple hue over all my rocks. It's sort of appealing to the eye, but I'm not sure what it is. It is darker more than anything. My main question for the forum is, can anyone describe the progression of what coralline algae growth is supposed to look like?

I would think it's spots of purple here and there right as it starts to grow, and then just spreads. I would not think it starts out like the color I'm describing, and then changes from there. I really don't know. Thanks.

Johniejumbo · Nov 8, 2019

Mine always starts as spots of pink or purple or whichever color it is and blooms out from there. Doesn’t really change color much

Lester Verano · Nov 8, 2019

Johniejumbo said:
Mine always starts as spots of pink or purple or whichever color it is and blooms out from there. Doesn’t really change color much

Do you do anything to help it along?

stanleo · Nov 8, 2019

I am not an expert but I think it grows exactly like you describe. Does what you are seeing come off with a light scrub? If it does than I think that is some form of algae or cyano. In my 9 month old tank the coralline is growing mostly on the back of the tank and the over flow box in circles that gradually get bigger. But I could be wrong.

Lester Verano · Nov 8, 2019

stanleo said:
I am not an expert but I think it grows exactly like you describe. Does what you are seeing come off with a light scrub? If it does than I think that is some form of algae or cyano. In my 9 month old tank the coralline is growing mostly on the back of the tank and the over flow box in circles that gradually get bigger. But I could be wrong.

Yes it comes off with a light scrub. And I too think it's Cyano.

Westoncase · Nov 8, 2019

It takes effort to get coralline off

stanleo · Nov 8, 2019

Lester Verano said:
Yes it comes off with a light scrub. And I too think it's Cyano.

Then I would say it's cyano. Coralline algae grows naturally with no interference from us. If your calcium and alkalinity levels are right for it to grow, then it will grow. At least that has been my experience. Again, not an expert on the subject. And frankly, I don't know what the "right" levels would be.

Westoncase · Nov 8, 2019

Also coralline has to be introduced, it doesn’t just appear outta no where. Atleast thats what ive been told

SuncrestReef · Nov 8, 2019

I believe most of my coralline came from snails and frag plugs that were covered in it when I introduced them to my tank. As I go back and look at old photos of my tank, I didn't see any coralline on my rocks for the first 7 months, then it started popping up as small specks that spread slowly. Around 11 - 12 months it just exploded and was everywhere. Mine is bright pink:

7 months:

9 months:

13 months:

krash7172 · Nov 8, 2019

Are you wanting coralline? I only ask because many don't. Some people somehow grow thick layers. There are also different types of it. I bought a small rock from my LFS that had a nice color of coraline on it. 2 yrs later it is covering most of the tank that gets proper light. I like it. I use Fritz Red, 1.0245 SG and 10.0 Alk.

SuncrestReef · Nov 8, 2019

The right back wall of my tank was completely covered in coralline because scraping that side was inconvenient due to the adjacent wall. But lately I've notice several areas growing colonies of bubble algae, and an attempt to pluck them off ended up cracking a large section of the coralline. It turned out the coralline was really thick, but not actually attached to the back wall, so it came off in large chunks:

krash7172 · Nov 8, 2019

Ya. That's the thick layer stuff that maybe people don't like. It's all personal preference. Mine is very thin layer and has never flaked. It's a light purple color under lights.