I think I'll have to try Alternanthera renekii again. I tried it a few years ago and never had any luck with it.
Sorry. I totally forgot to answer this. I know it was a long time ago, but here is what I have seen so far. I had DIY CO2, ferts in the water column, and medium light on it. It seemed to love it, from my experience.
Ok. I am still alive. I actually just moved the tanks around today. I moved the rack over a bit. Put the salty tank in place of the 20high, and put that tank on the bottom shelf of the rack. I will probably replace it with a 20 long or a 29 gallon tank. Not sure. I will probably post a pic tomorrow. Ya know, after the end of the world and all that.