Coralline Algae

Instigate · Jan 6, 2018

My tank has been up for about 7 months. I'm getting splotches of purple coralline all over my rocks and yesterday I noticed some very bright pink coralline that fluoresced under the actinics. And the largest growths of it were growing over the purple. But now today around noon I noticed all the pink stuff had turned off white. All the purple is still there. I still see a small amount of the pink here and there but it seems to be dying back. What's the deal? I didn't do anything. Literally all I've done this week is feed fish. All corals are happy with great PE.

Last parameter check was about a week ago:

No3 - 1 ppm
Po4 - .25 ppm <- High I know, just started some chaeto and if that doesn't bring this parameter in line I will start gfo.
Ca - 420 ppm
Alk - 9 dKH
Mag - 1470 ppm
SG - 1.026
pH - 8.4

jsker · Jan 6, 2018

Your system is going to go through all kinds of ups and downs and Corrine is on for them. Your parameters look pretty good and yes the phosphates need to come down and the nitrates need to come up. I would suggest using a couple of doses of Lanthanum chloride to bring the phosphates down. I would say your rock is leaching Phosphates.

nautical_nathaniel · Jan 6, 2018

I wouldn't fret too much about coralline algae going back and forth from growing and bleaching suddenly, I find it to be fairly finicky on it's own and not a good indicator of anything being wrong with water parameters, lighting, etc. I've noticed that if my urchin ever eats any of a large coralline patch, the whole patch will usually bleach/die off and then bounce back a week later as if nothing happened. I've had just about every color of coralline algae in my tank and it seems that certain colors will grow better than others sometimes and then the next week a different color takes over as the dominant grower in my tank.

Instigate · Jan 7, 2018

jsker said:
Your system is going to go through all kinds of ups and downs and Corrine is on for them. Your parameters look pretty good and yes the phosphates need to come down and the nitrates need to come up. I would suggest using a couple of doses of Lanthanum chloride to bring the phosphates down. I would say your rock is leaching Phosphates.

You have a preferred brand?