BTW--It all depends on light duration. Some use as much as 10-12 hours, others as little as 7. See what works best for you. A nice thing to do is use a timer to split the hours its on. Supposedly this helps prevent algae and lets the tank be on during times you're at home.
Gday sunny good to see another aussie in here! * Oops didnt see that light question was already answered* About the plants you have jus about 1wpg so low light plants are best as mr_miagi32 explained hygrophila polysperma, java moss, java fern and maybe some water sprite would grow under your conditions...