# Coraline Algae in an African Cichlid Tank



## fishestate (Jul 7, 2015)

Hey there!

So I've got an album with pictures of a few rocks that might possibly be growing some type of coraline algae.



http://imgur.com/DFjUR

 (sorry for the nosy juveniles)

Here's the text info in the album:

_Pictured below are several rocks that seem to have coraline algae. I've been watching this grow very slowly for about six or eight months. It only grows below my actinics that I run at night for "night time" effect. Because it looks cool. I decorated the tank like an idiot so I do not have sand or crushed coral substrate. As such I did add some dried coral pieces from the LFS to help with the pH. The pieces had some little red patches (not pictured, they're not visible in the rock arrangement right now)._

I am not trying to say difinitively that it is coraline algae. I understand what coraline algae is (am also a nanoreefer). I searched this forum for other posts about it, found this:

http://www.cichlid-forum.com/phpbb/viewtopic.php?f=7&t=255076

Unlike that OP the coraline algae is not hairy, not fuzzy, is not cyanobacteria (i know that very well), is not slimy and does not grow "3-dimensionally." It seems very, very much like coraline algae.

Other than the actinic blue light (specs for which i dont know), I use power-glo 18000k, 580lumen, 7500 h.

In terms of minerals I use Seachem Cichlid Lake Salt, Seachem Malawi/Victoria buffer (have also used Reef Buffer in a pinch when out of cichlid buffer), I do 2tbs of epsom salt for every 5gal, and prime conditioner.

I feed NLS and home-made cubes of spinach/garlic.

Thoughts?


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## Narwhal72 (Sep 26, 2006)

Generally coralline algae will not grow in freshwater (it is a marine species after all) mainly due to the fact that the solubility of calcium carbonate in freshwater is so much higher that the skeleton simply dissolves away and kills the algae.

However in your tank with the old live rock and additional buffers it probably has a very high GH and KH and may functionally be like saltwater in preventing the calcium carbonate from dissolving. It may be a type of marine coralline algae has adapted to survive in these harsh conditions (for it).

Or it could just be a benthic red algae.

Andy


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## fishestate (Jul 7, 2015)

Thanks! I'll look into benthic red algae and see if that fits--- ok I looked it up. I don't see any images that look anything like what I'm describing. It's not a bad guess, but it seems like they grow in a more "3-dimensional" way, rather than flat on the surface. The closest image would be this: http://www.marbef.org/wiki/File:Fig8Rindi.jpg but that too is a bit more "3dimensional" than what I've got. This page has a lot of information on red benthic http://www.marbef.org/wiki/diversity_an ... thic_algae but nothing that seems to match what i've got.

I totally agree with you- coraline algae does not survive in freshwater for the exact reason you describe (awesome, btw).

The old live rock and varius mineral buffers are exactly what I was thinking could be the cause. I thought that maybe those elements plus the blue lights and the purple lights might be creating the perfect storm of conditions for coraline.

Because you mentioned it, I did a KH and a GH test. I'm not super sciencey and am not sure how to properly read the results, so I'll tell you the # drops (API test kit)

KH - 12 or 13 drops (200-400ppm i think)
GH - Seems like this old bottle has gone bad. I put in 40 drops before I gave up. I looked it up online and the GH does go bad pretty quickly and this bottle is at least a year old.

Thank you andy!


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## fishestate (Jul 7, 2015)

Ok. Following the "benthic red algae" from Andy, I found this: http://www.marbef.org/wiki/File:Fig8Rindi.jpg which is actually pretty identical to what I have. fun fact: coraline algae is a benthic marine algae.

(The info on benthic red algae is about halfway down the screen on this page: http://www.marbef.org/wiki/diversity_an ... thic_algae )

I got a look at the original dead live rock and found some on a lighter patch of rock and it matches the top picture very closely. I'll share a picture if I can get a good one.

Thanks again, andy! You really pointed me in the right direction I think.


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## Narwhal72 (Sep 26, 2006)

Benthic just means it grows on a surface. As opposed to pelagic (which floats around).

Afraid you would really need to use a microscope to really see the cell structure to tell what it is for sure. But if it ever dies and leaves behind a white skeleton you will also have your answer.


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## Fogelhund (Dec 3, 2002)

I gather you have something similar to this?

http://www.aquariumforum.com/f5/red-spo ... 14923.html

I've had that for several decades, mostly grows on the glass, but spreads VERY slowly. If you scrape it off with a razor blade, it often just doesn't return. The link doesn't specify exactly what type of algae it is, and I don't know either.


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## fishestate (Jul 7, 2015)

Hmm. Interesting Fogelhund. None of mine is on the glass, but that could very well be the same thing. It's all over the glass in my nano. On some of the lighter-colored rocks it appears more pink than deep red. I will try to make good on my promise to include some more pictures of it on the different rocks.

Narwhal- thanks for pointing out the difference between benthic and pelagic, clearly that distinction didn't sink in when I was reading. my wife and i were literally discussing just hours ago that we want a microscope for exactly this type of situation. seems like a good plan.


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## fishestate (Jul 7, 2015)

I added more photos to the album


http://imgur.com/DFjUR


Also I brought the conversation over to http://reddit.com/r/reeftank since they have more experience with coralline algae. Their general consensus was that it is most likely coralline algae. Without a microscope we can't be sure, but the lighting, calcium, alkalinity, salinity and pH are all in the right range to support coralline growth.

If that is the case, do you think this would be something other cichlid folks might want in their tank? I mean, I love the way my salt tanks look with their red and pink and purple rocks. Do you guys think I should bring it to swaps or something like that?


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