IDEALLY, yes, >2W/Gal.
This would be considered I think a minimum to keep most types of plant happy and also get some of them to 'pearl'.
Can you put your tank in direct sunlight? This would help 'up the watts'.
Having less than 2W/gal does not mean you just simply cannot keep plants though! It is just that you may be a little limited in your choice to the more hardier plants. Hence consider & research these:
Java fern (Microsorum pteropus)
Java Moss (Vesicularia dubyana)
Amazon sword (Echinodorus bleheri)
Dwarf Anubias (Anubias barteri var. nana)
Tropical Hornwort or Coontail (Ceratophyllum submersum / Ceratophyllum demersum).
Carolina Fanwort (Cabomba caroliniana)
Water Wisteria (Hygrophilia difformis)
Cryptocoryne wendtii
Dwarf Hyrophilia (Hygrophila polysperma)
Thai Onion Plant (Crinum thaianum)
Dwarf Sagittaria (Sagittaria subulata)
You could do an awful lot with that list! (I have done much with only 3 out of the list!)
Those plants would do fine in a 'low tech' tank: i.e. one with no CO2 & lower lighting levels. Obviously upping the watts & adding CO2 will make them thrive. I have 2W/Gal, no CO2 and my plants are thriving. I use 1x 15W Arcadia Freshwater bulb and added a second 15W Arcadia Original bulb (which is labeled to improve planting conditions).
Andy
PS
When you get plants, FFS clean them in 5% solution of bleach. Then clean them agian in normal water. Also clean them of any friggin SNAILs and their damn eggs (looks like tiny glob of clear snot).
This will prevent an outbreak of a) sodding Algae, B) sodding snails.
