George Farmer said:
I'll be setting up a seagrass tank for seahorses early next year. Can't wait!
What grass are you using, George?
Back on topic, yes, you can do a macro algae tank and yes, tanks that have dense macro growth don't require the LR that say a typical reef does. I still have some.
The "easier" seagrasses tend to be Halodule and Halophila. Most require a deeper sand bed, but these two will be fine with about 3-4" which is what I currently have. Nutrient rich or not is up to you. They'll probably grow faster on a nutrient rich substrate, but I'm not unhappy with the growth I'm getting from just using a nice fine oolite sand and feeding the tank inhabitants daily doses of frozen foods. I'm really getting some good growth now that my tank is older and I've switched to metal Halides. I have a Halodule species, shoal grass. I liked the delicate look of it. The lighting must be good, and the kelvin temperature of the bulbs not as blue as what some reef keepers prefer. I have a 14k Halide. Nice color, good growth. Good compromise.
Of the Caulerpas, I personally like C. prolifera best. The thing with macros, is that you really do need to be on top of the pruning. I've only had a bit go sexual on me and I knew what to look for, so I was able to remove the portion that had gone sexual before the gametes were released. I've not had anything go sexual since, but I prune a lot. Something to think about if you decide to go into this. The sea grasses won't require so much until they are established, but macro! Haha, that'll need pruning on a regular basis. What macro you want is up to you, but be aware some are coldwater species and most of us keep tropical SW tanks.
I'm enjoying my tank. It's very diverse and fun to keep.
L