Lots of light seems to do the trick. I'm having decent success with an outdoor tub holding Thalassia. (I think they would be doing better if the salinity swings weren't so crazy, its been really dry here in FL lately.)
The article is a good start (if I do say so myself) but if you have further questions, feel free to ask. I can also mine up a few good threads if need be.
I have thallasia in only 3'' of sand but is a very mature sand it was beach sand collected by me and also the thallasia and they where only 4'' tall and now are like 12''. Also my lighting are 192w pc and they have grow very nice. Sorry for my english it is not my first language.