this is , simply, Not true.30ish watts isnt really going to be able to grow any plants no matter the spectrum.
I grow plenty of plants in a 55 with a stock light, 48" t-8 bulb.
if you go with low light plants you can grow plenty.
Java fern (3 varieties)
several mosses
Anubias several specie
Cryptocoryne
bolbitus
just to name a few