Coraline Turning White?!

[nick76]

Hmm well my tank is 9 months old and my back wall is covered with spots of purple coraline algae along with most of my rock. About a week ago im starting to notice alot of it is begining to turn white?
Whats going on!? :scared:
Nitrites: 0
Ammonia: 0
Salinity 1.025
Calcium: 450
PH: 8.4

 

[trigger11]

I am interested in hearing the response to this as well. I had green coraline color growing for a few months. Then it finally switched over to purple after I got a new MH light about a week ago. Now, I have one little rock that is turning all white.

 

[reefkprz]

what are your phosphates at? phosphates can be very detrimental to coraline.

 

[spanko]

Phosphates, Calcium, Alkalinity, and how old are your light bulbs? Any problem with any of these things could affect your coraline.

 

[nick76]

Ahh could be phosphates... I do not have a test kit for that and my alk test kit just ran out... Ill get some supplies tmro and post the results.
My bulbs are less than 6 months old i know that.

 

[jerthunter]

My observation is that coraline algae needs a good level of alkalinity. Another reason it might turn white is if you recently upgraded your lights or had a big temperature swing.

 

[reefkprz]

IME
coraline will bleach for a couple reasons, sudden Increase in lighting, bad (low)alk, high phosphates (will also kill coraline not only bleach it), BIG temp swings (a couple degrees wont cause this), extremly low calc levels.

 

[cgrant]

I always had a hard time getting my coraline to boom before i added my calcium reator, I really think that my coraline is booming now because the reactor is keeping my alk ~11dkh, my ca ~420 and all the added from the media in the reactor. I tried everything i read, could think of, etc but couldnt get my coraline to really boom until the reactor.
If it is turning white thats not good! Need to figure out what is wrong.
I test for
alk
ca
phos
mag
nitrate
I dont even test for ammonia or nitrite anymore unless i think something is wrong in the tank.