Java Fern and Java Moss are low-light plants, so they will do better either in less overhead light, or when shaded by floating plants. Almost any tank lighting will accomodate these, except bright overhead light with no shade.
Vallisneria tends to need brighter light, but more importantly harder water. So depending upon your GH, it may be doing well because it is getting what it needs in both light and hard minerals.
On LED lighting, I won't say much but leave it for those with more experience to comment. I have however heard that the Marineland Double Bright LED system is fine for low and moderate light plants. I believe someone mentioned this fixture in another thread only this week.
To other plants. With moderate light you could have success with pygmy chain sword (Helanthium tenellum), the common sword (probably Echinodorus bleherae), and crypts. Stem plants tend to need brighter light because they are fast growing, but some manage quite well in moderate. Pennywort is one I find works, and it also is very nice floating. And floating plants in my view are essential in most tanks because they are much appreciated by forest fish.
None of the afore-mentioned need added CO2. I have never added CO2 to my tanks in more than 20 years of well-planted aquaria. Other fertilizers may be needed, depending upon the plants, light, and your water and fish load (which both supply some nutrients). A comprehensive liquid is the first to use.
Last edited by Byron; 09-21-2013 at 08:43 PM.
Byron Hosking, BMus, MA
Vancouver, BC, Canada
Something we all need to remember: The fish you've acquired was quite happy not being owned by you, minding its own business. If you’re going to take it under your wing then you’re responsible for it. Every aspect of its life is under your control, from water quality and temperature to swimming space. [Nathan Hill in PFK]