Juwel's supplied tubes aren't very good for plant growth.
Personally I would swap to full-spectrum types as described in my lighting article. Fit Juwel or Arcadia reflectors to improve intensity.
A cheap source of full-spectrum tubes can be found here, I intend using these when I replace my current tubes -
http
/www.fishforums.net/index.php?showtopic=107609&hl=
You should be able to grow easy stem plants and the classic list of low-light plants (Anubias, Java fern, Crypts) with your lighting levels.
A good friend of mine has a Juwel Rio 240 with the same lighting (2 x 38W) and Juwel reflectors. He has kept the supplied warm white tube and swapped the cool white for an Interpet Triplus with good effect. However, he does use a laterite enriched substrate and DIY CO2 as well - something worth considering if you want the best for your plants. His plants are very healthy, mostly easy stems and Amazon swords and he has no algae problems.
