Macro is a great addition to a fish only setup, agreed. Some different types to consider maybe caulerpa racemosa, caulerpa prolifera, halimedia, shaving brush, umbrella, mermaids fan, red kelp, red grascellaria (sp?), pink galaxea (sp?) red grape caulerpa, and perhaps even mangroves. Take note from freshwater planted tanks - they use small plants in front, medium plants in the middle and tall plants in the back. You can really aquascape and prune macroalgaes to look really awesome in a tank, but if you let them grow out of hand, it can be a real eyesore. Most planted fish only tanks have more of a benefit if you use pink lights or plant grow lights than our regular white/blue combinations we use for reef tanks. Good luck and I hope this helps!