The WPG rule kind of breaks down in tanks under 10g so you need a lot of wattage to grow even low-light plants. If you are just screwing a CFL onto a current fixture that would probably set you at low light. Installing an Coralife Aqualight Mini (18w) would give you medium and purchasing a Hamptom Bay Desk lamp to use (27w) would give you high light.
kelly... whats a CFL? and where do you get it.. how much etc etc.
I would like to eventually plant my 3 gal tank. I believe my eclipse 3 has a bulb of 15w. I'm only putting a bit of java moss and a java fern or two in the tank if at all so I only need a low- med light set up.
Eclipses come with an awesome light. You should be able to swing some low to low-medium light plants no problem. Just don't forget to supplement with a good micro-fert like Flourish Comprehensive and ensure that the gravel has some sort of nutrient source like flourish tabs if you are not going with a planted tank substrate like Eco-Complete or Flourite.
Thanks Kelly.. I'll def make sure to get the ferts when I plant it. It won't be for a while bc I'm planning on taking sections from my 10 gal and transferring them.. so I need to plant the 10 gal first LOL