yep, wpg is watts per gallon.
maybe bumping the hours per day up would help though. I'd do at least 12 hours with that amount.
the nutrients necessary for planted tanks are:
Traces (lots of stuff in it, including iron (Fe))
PO4 - need in a range of 1-2ppm. Testkits are reasonably priced. Can dose with KH2PO4
NO3 - need around 20ppm. a little higher wont hurt. Testkits are a must.
Traces - need to dose about 5ml per 20g's (20ml for you) 3x per week. Can either use Seachem Flourish ($$ adds up though) or CSM+B
Mg - tap water generally has enough of this, but I find it good to give a "booster". Just add about 1t of Epsom Salt (MgSO4) after each 50% or so water change.
Ca - tap water generally has enough of this too. Do a test for GH (General Hardness). If you have at least 6-7 degrees GH then you are fine. If less, then buy Seachem Equilibrium and add whatever is recommend. This will take care of Mg as well. GH is the combo of Ca/Mg in your tank water (or tap in that case)
K - you will generally get enough of this if you consistently dose NO3 (w/ KNO3) and PO4 (with KH2PO4), but can also dose some K2SO4 to give it a boost. Aim for 20ppm per week of dosing K. It gets expensive dosing K with what you are currently using. It is easiest to dose with things like K2SO4.
All of the above you can obtain from www.gregwatson.com
very very cheap.
Do some searching around on this forum and you will find a lot of dosing strategies.
This is just the beginning, so ask more questions as necessary.