Coraline turning white
 

Latly Iv noticed that my coraline growth has stopped and the purple coraline turning white. Im puzzled as Im doing nothing diffrent I maintain a 440 calcium lvl using purple up and the only thing I can think of is I did a bulb change a few weeks ago but I cant see how that would stop its growth? Could it be the vitamin suplements im adding?

Has it been exposed to air ? I know coraline if it sees much if any air will die.

I think it may have to do with your lights. In my tank I am having troubles growing coraline even though my sps corals are growing well. I seem to get decent growth in the more shaded areas but the bright areas are struggling. I have 250 watt mh and t5 and my parameters are bang on.

+1 on growing better in shade

Mine went white when i changed up my lights too , it will come back.

If it is white, it is no longer algae. The white is simply the carbonate foundation built by the algae.

Many things could be causing this - not enough blue/too much white light, exposure to air, drop in KH, reduction in Calcium, change in water flow, shading, or nuisance algae growing over it.

To grow back/more, Increase the amount of actinic lighting, and the duration of the actinic lighting. Tune down white spectrum if possible (SPS permitting), Make sure calcium is around 400-420, make sure magnesium is around 1300. Turn away power-heads from locations where you want coraline to groww, it does not like high flow.


One thing to also consider is when scraping algae, mind the coraline. Just because you scrape gently enough just to remove the green stuff, it doesn't mean you are not killing off the coraline as your scraper passes over it.

Good luck.

Maybe check your Mg. I was treating a bryopsis problem by increasing my Mg and it made my coraline take right off.