I'd be less worried about getting red tips than just getting that crap to grow at all. If your lighting is too low or the bottom of the plant gets shaded, it just turns black and melts, leaving the top of the plant to float around. Lame.
I am debating trying some out in my 75 gallon tank, which is at around 2.3 wpg right now (3.6 when all the lights are on). The glosso grows fine, so I imagine the d. diandre might, too.
Two 1 GA desktops, a 5 gallon, a 2.5 gallon, a 10 gallon, a 20 gallon, a 25 gallon, and two 75 gallon tanks, all planted.
I am an expert on algae, so ask me if you have questions. I know how to grow it, just not how to get rid of it.