losing my purple color on my rock

[damsel]

I have had this rock for about 4 months, all of a sudden last 3 days all the purple turning in to white looking sponge and desinegrating, now rapidly in last 8 hours,
I checked water with lfs and they said my parm good. then I put it higher under the lights (not metal halide or anything to cool that would fry it) then went to food store and got some ro did a 6 gal water change (i know it was not much) the only thing I have done different is give my tank the smelly black powder but only a little 1/2 tea spoon and I have done this twice and phytoplankton.
It is happening so fast that by monday all my rock will have lost its color (coroline)
oh sorry for the miss spelled words

[Doug1]

If you have had the rock 4 months and it just recently started I would suspect the recent additives. Are we talking "black Powder" the Marc Wiess additive?.
Also does your LFS test for calcium and alkilinity levels, using decent test kits?

[yardboy]

I didn't quite understand your statement about th elight. I not so intelligently replaced my 12000K sunburst with a 10000K Ushio a week before I went on vaation. Left the timers the same. Two weeks later, my Fungia is pink and white, my brain is bleached on one side toward the light, and a large percentage of the corraline, particularly the purple, is bleached too. Didn't think it would make that much difference, but it did. Fortunately after only one week of shorter photoperiod, I can see definite recovery, and nothing has died.

[Casey]

Yardboy the 10k is much brighter than a 12k becareful or you will turn it all white.Been there done that.

[sam]

yardboy how do you like the 10 k compard to the 12k ? do you have any actinic with those also . sorry to go off topic .

[Geoff]

i have large areas of coraline algae go white on me, but they recover over time. i also do not have any purple anymore. it seems to like a different spectrum or intensity then what my system supplies. i get lots of the pink and maroon coraline. i have found that coraline growth is heavily dependant on Ca levels. if they drop the coraline will die off before any coral show any real stress. i also suggest testing your Ca and alk levels.

G~

[damsel]

yes, on the black powder, that is the one and my ca levels were fine but I did add some buffer to help with the ph and maybe that did it. I do remember I also had just started with the buffer only did that about a week ago and none since, could that have done this?