I think white balance is the least of your problems at this point. Who really cares about minute color variations when you can't even see the subject. Your coral is just a blurry mess. It also looks like it may be bleached (but I don't know that it is). When shooting a subject that is almost a uniform white, trying to pull details out of it is difficult at best.
A) Use a tripod
B) Get your shutter speed up
C) Underexpose the image
D) EDIT YOUR IMAGES IN PHOTOSHOP. You are NOT going to get it perfect in camera, don't even try. They will need level changes, color adjustments, burning, and all sorts of other tricks to make this look right.