Skip the tabs. Since you've got a normal gravel substrate, choose plants that aren't big root feeders. This really doesn't limit you terribly, although it means no vals, crypts or Echinodorus. Anubias, java fern/moss, stem plants, floating plants will offer much in the way of variety. Check out the second picture in my sig. The 18 gallon is a new setup, really my first try at a 'low tech' setup. I'm using Hydrocotyle leucocephala as a carpet plant and so far it's working fantastically. Just bury the stem in the gravel and very gently pull it up to re-expose most of the stem.
All these plants will draw the majority of their nutrients from the water column.
Once the tank has been set up for a while, you should have enough mulm in your gravel to accomodate some root feeders, but until then, there's plenty of variety among the column feeders.
All these plants will draw the majority of their nutrients from the water column.
Once the tank has been set up for a while, you should have enough mulm in your gravel to accomodate some root feeders, but until then, there's plenty of variety among the column feeders.