lighting for a grass bed

[jadeguppy]

p.s. I gotta say those showerheads are cool looking. I've been thinkig about a way to install more lighting over the shower and those look sweet.

 

[jadeguppy]

Update: I think I have narrowed it down with your help. How will these compare?
three 3' 6500k (11w led=30w reg) 3m=63 lux (specs I was given) vs.
150w mh clip on light, probably 14000k

reminders: tank is 24" deep, so probably figure 22-20" of water. I'm wanting to grow seagrasses. It is a seahorse tank. Heat can e a problem and I don't want to get a chiller.