coral disease

[nurse shark]

Although I am fairly new at this reef hobby, I am committed to learning all that I can. My reef has been set up for over a year now with good success. Recently though I have been seeing some disturbing occurrences. One of my Acropora bottlebrush type corals has started to decline after a year of constant growth. This occurrence has folowed the death of another Acropora in the near area. Observations of this decline are as follows- 1. Polyps appear not to extend out as far as normal
2. Polyps stop extending all together 3. White band of bleaching occurs at base 4. Bleaching progresses up the coral until complete death. I would like to know possible etiology/treatment of this ailment. Do you think that I should cut the bleaching area out in hopes of saving the colony? Will this bleaching spread to other corals? Thanks for any advise that you can give.

 

[blstravler]

What are all of your tank parameteres? Including temp, type of lights, etc.

Also how much flow do you have in your tank?

 

[wentreefgirl]

Any changes to the tank recently. New coral, change in salt, lighting bulb change?