I've heard a few cases where the Piranhas eat the leaves off plants. I guess we'll see.
Ya Im thinking java fern, anubias, amazon swords. I dont know about the vals, I haven't had much luck with them.
If I use two DIY Co2s would that work? I'm also thinking about getting another 100w or so PC light, that would put me over 3 WPG.
What is the best substrate to use? I've heard of people using like a dirt or soil, I dont know much about it though. Right now I have home depot sand in most of my tanks, I think it looks nice and natural.
Any other thoughts or suggestions?