Which plants carpet
Dwarf sagittaria is the easiest and carpets without CO₂, slowly. Dwarf hairgrass and Monte Carlo form denser lawns and grow far better with CO₂ and bright light. Moss tied to mesh makes a carpet that needs no special light. Pick by your light first: the bottom of a tall tank gets much less light than the top.
Planting
- Use a fine substrate: a plant soil, or fine sand with root tabs. Coarse gravel lets small plugs float up.
- Split each pot into small plugs of a few stems with roots attached.
- Push each plug in at an angle with long tweezers, an inch or two apart, and cover the roots.
- Run the light 6 to 8 hours a day at first and change water often in the first weeks: new plants melt a little and free nutrients that feed algae. Plant melt.
Keeping it
Trim a thick carpet like a lawn, close to the substrate, before it lifts in a mat and the bottom layer dies. Siphon debris lightly from the surface. Yellowing in a carpet usually means it lacks nutrients or CO₂; pale patches that float up mean the roots never anchored. CO₂ for planted tanks · Start a carpet before you fill the tank.