about the bubbles... you might try boolean-ing a small sphere from a larger one to create a hollow sphere. Then give it your glass texture. Should help avoid that 'crystal ball' look. if you do a search for DOF in this forum, I believe you'll find that it's the general consensus that DOF is not one of Bryce's strong points. Most prefer to render a distance map, then add the DOF in post-work - but for this month's challenge that is out. You might try setting the focal length a little closer (if you haven't already) and maybe get the rocks a little more in focus, without blurring the fish and eggs to badly.