New issues

[danny zubot]

About a week ago a patch on one of my completely coraline encrusted rocks bleached out. A few days ago a whole colony of zoos began to change from their usual green and bluish color, to a yellow color. I guess they are bleaching as well. All other corals are fine so far, I'm hoping this will stay localized. Any suggestions or comments as to why this would happen just in these two spots?

Additional: my Ca was a bit low (300ppm) for a day or two last week. Did water change and prostrata acro spit slime all over tank.

[Beverly]

Danny,

Just going to ask the usual questions....

Are you using tap or RO water? Have you tested your NSW for alk, Ca, Mg, SG, pH, temp before adding it to the tank? What are alk, Ca, Mg, SG, pH, temp in this tank right now? How often do you test for and adjust alk, Ca, Mg, SG, pH?

Also, I recently discovered that my Salifert Mg kit was out of whack. I kept getting test results that showed my tank was continually low Mg levels, so I kept adding what the Reef Chemistry Calculator told me to add. Then I got a new test kit. Dang, if Mg in all my tanks measured 1500+ ppm. Needless to say, it's a good idea to make sure tops on liquid solutions should be on tight, and make sure test kits are not outdated before relying on the test results.

[danny zubot]

Well, all of the usual levels other than CA have been fine. Since posting this origianlly the coraline that had bleached has begun to turn purple again. The zoos are still pale but fully opened so I guess they'll recover. I'm still leaning toward chemical warefar in the tank.

[christyf5]

Is it possible the slime landed on those two areas and just happened to do some damage there? I'd bet thats what happened. Do you run carbon?

[danny zubot]

I think you are right. I do run carbon but i think it was a bit old at the time this all happened. I can understand the zoos bleaching but I didn't know that coraline would be effected the same was as a coral!