Nice looking corals.
A few suggestions if you're interested.
- Some of the images could be sharper and I'm seeing shutter speeds of 1/20-1/30, which makes me think you are hand holding. If so, try using a tripod and remote shutter release or self timer.
- Turn off pumps before shooting (reduces subject movement, encourages polyp extension and reduces marine snow)
- Many people find out of focus objects in the foreground distracting. Composing the shot such that the primary object / area of interest is in the foreground and setting the focal plane there is generally a good thing.
- Avoid center composition
- Remove marine snow from your images. Doing so really improves the look and feel.