Monte Carlo (Micranthemum tweediei) is a low, spreading carpet plant with small round leaves, and the most forgiving of the popular aquarium carpets. It’s the one to choose if you want a green lawn without the demands of HC Cuba, tolerating slightly less light and even limping along without pressurised CO₂, just more slowly.
What it needs
- Latin name: Micranthemum tweediei
- Type: carpet / foreground
- Light: medium–high
- CO₂: beneficial, and effectively required for a tight carpet
- Difficulty: medium
- Growth rate: medium
Growing Monte Carlo
Plant small portions spaced out across the substrate rather than one clump. Under good light they send out runners and knit together into a mat. A nutrient-rich substrate gives the roots something to work with. As carpets go it’s among the easier ones, slightly more forgiving than HC Cuba, which is why it’s the carpet most beginners should start with. For the full comparison, see our carpet plants guide.
Getting it to carpet
The two levers are light and CO₂. Strong light reaching the substrate keeps growth low and dense. Added CO₂ tightens it into a proper flat carpet. Without CO₂ it still grows, but slower and looser, and may reach upward rather than hugging the floor. If it starts growing tall, that’s the signal it wants more light down low.
Monte Carlo questions
Is Monte Carlo good for beginners?
It’s the best carpet to start with. It’s the most forgiving of the popular carpets, though it still wants decent light to stay low and spread, so it is beginner-friendly by carpet standards rather than no-effort.
Does Monte Carlo need CO₂?
It’s beneficial and effectively required for a dense, tight carpet. The plant survives without it, but grows more slowly and less compactly, so most people running it as a true carpet add CO₂.
Monte Carlo or dwarf baby tears?
Monte Carlo has slightly larger leaves and is more forgiving. dwarf baby tears (HC Cuba) gives a finer carpet but is an advanced plant. For a first carpet, Monte Carlo is the safer choice. Dwarf hairgrass is the grassy alternative.