What kind of lights are you running? If you have too much light you'll end up with your plants coverd in algae without co2.
For my low light low tech I found either a single bulb or double bulb florecent will do the trick. How much light depends on the size of the tank. I've grown anubias in very low light. They grow really slow too much light and they get coverd in algae. Ditch the background and just paint the back of your tank black.
Heres a list of low light plants.
Java Fern - Microsorum pteropus
Windelov Java Fern, Windelov Fern - Microsorum pteropus 'Windelov'
Narrow Leaf Java Fern - Microsorum pteropus v. 'narrow leaf'
Java Moss - Vesicularia dubyana
Green Hygro - Hygrophila polysperma
*Sunset Hygro - Hygrophila polysperma 'Rosanervig'
Ceylon Hygro - Hygrophila polysperma 'Ceylon'
Rotala Rotundifolia - Rotala rotundifolia
Rotala Rotundifolia sp. Green - Rotala rotundifolia sp. 'Green'
Rotala Indica - Rotala indica
Hornwort - Ceratophylum demersum
Parrots Feather - Myriophyllum aquaticum
Moneywort, Water Hyssop - Bocapa monnieri
Brazilian Pennywort, Pennywort - Hydrocotyle leucocephala
Crypt Wendtii - Cryptocoryne wendtii
Crypt Balansae - Cryptocoryne Balansae
Pygmy Crypt - Cryptocoryne pygmaea
Guppy Grass - Najas guadalupensis
Anubias barteri - Anubias barteri v. barteri
Anubias barteri 'marble' - Anubias barteri 'marble'
Anubias barteri v. 'glabra' - Anubias barteri v. 'glabra'
Anubias nana - Anubias barteri v. 'nana'
Coffee leaf anubias - Anubias barteri v. 'coffeefolia'
Crypt retrospiralis - Cryptocoryne retrospiralis
Crypt spiralis - Cryptocoryne spiralis
Golden nana - Anubias barteri v. 'nana golden'
Narrow leaf nana - Anubias barteri v. 'nana narrow leaf'
Petite nana - Anubias barteri v. nana 'petite'
Philippine Java Fern - Microsorum pteropus 'Philippine'
Red Java fern - Microsorum pteropus "red"
Crypt Becketii - Cryptcoryne becketii
Pelia - Monosolenium tenerum
Waterwheel Plant - Aldrovanda vesiculosa
Bacopa - Bacopa caroliniana
African Water Fern - Bolbitis heudelotii
Hornwort - Ceratophyllum submersum