Coralline bleaching after supplementation

Longchamp

New member
hi, i just picked up parts 1 and 2 of DT's new 3 part (Ca, Alk, and Mg)

The Part 1 is liquid CaCl. Ive been dosing it fairly slowly, and gotten my Ca up to 440 and my coralline looks like its starting to bleach out. I've been adding the Alk portion, but slower. I just tested today. My Ca is 440 and my alk is at 10dKH. I don't have a Mg test kit. Is the Chloride reacting with my magnesium and dropping it? Im guessing not since Randy's recipe calls for minimal Mg supplementation.

Edit: I just remembered MgCl2 is soluble... so i guess its not that.
 

Randy Holmes-Farley

Reef Chemist
Premium Member
You sure it is bleaching and not just growing? Growing coralline is often covered in white lines or dots at the edges where it is actively growing.

Have a picture?
 

Longchamp

New member
I'll work on trying to find my camera. Large areas in the highest flow areas seem to be most affected. By large i mean the patches are over a couple of square inches in size.
 

sct2525

New member
I've had similar problems-see picture

I've had similar problems-see picture

I've had similar problems with my rock see picture below,Water parameters are PH-8.2, CA-445, Alkalinity- 9dkh, temp- 78, Phosphates- .02ppm, no algae in tank. I noticed white growth on live rock several days ago, this is very hard, difficult to scrape off even with toothbrush. I've also recently developed small hard white dots on my glass, about the size of a large pin head, not sure if this is related to the rock turning white in places. Does anyone know what this could be? It seems to be spreading on the rock.

See picture of rock:

IMG_liverock2.jpg
 

Randy Holmes-Farley

Reef Chemist
Premium Member
It is hard to tell, but did the white spots circled on the rocks actually have colored coralline living on them recently?

have you checked magnesium? Coralline deposits an unusually large amount of magnesium, and it may benefit from normal to high levels of it in the water.

The white dots may be new coralline colonies, or abiotic precipitation, or some other sort of organism.
 

sct2525

New member
I have not checked my magnesium recenly, I was waiting for the Salifert kits to come in at my local store. I'm not sure if corraline was living on the rocks where the white spots started, probably because I just noticed the white areas on the rock several days ago. I'm wondering if the flat white dots on my glass, which are very hard to remove even with my Algae Free magnet, are related to the white spots on my rocks.
 

Longchamp

New member
Thanks Randy, I think it's the tuxedo urchin eating the coralline. Ive got new coralline growth on the tube on my HOB filter so i dont think theres a problem.
 
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