Monte Carlo vs Dwarf Hair Grass: Which Carpet Is Best?

Few things look better in a planted tank than a soft green carpet rolling across the front of the glass. If you've started shopping for one, you've probably narrowed it down to the two most popular choices: Monte Carlo and Dwarf Hair Grass.

Both are fast growers. Both stay low. And both can turn bare sand or soil into a living lawn. But they look different, grow differently, and fit different tanks.

This guide walks you through how the two compare, so you can pick the right carpet plant (or both) with confidence.

Meet the Two Carpet Plants

Monte Carlo (Micranthemum tweediei 'Monte Carlo') has tiny, round, bright green leaves on creeping stems. As it spreads, it forms a thick, bubbly cushion that hugs the substrate. It usually stays around 1 to 2 inches tall.

Dwarf Hair Grass (Eleocharis) grows thin, grass-like blades from a base that sends out runners under the substrate. The result looks like a tiny underwater meadow. Depending on your lighting, it can stay as short as 3 inches or stretch closer to 8 inches.

So the first question is simple: do you want a leafy cushion or a grassy lawn?

Monte Carlo vs Dwarf Hair Grass at a Glance

	Monte Carlo	Dwarf Hair Grass
Look	Small round leaves, cushion-like	Fine grass blades, lawn-like
Typical height	About 1–2 inches	About 3–8 inches (shorter with stronger light)
Growth rate	Fast	Fast
Light	Moderate to high	Moderate to strong
CO₂	Does best with it	Optional, but helps
Temperature	About 74–82°F	About 70–83°F
pH	About 6.5–7.6	About 6.0–8.0
Spreads by	Creeping stems	Runners under the substrate
Care level	Medium	Easy

Both plants are happy in a typical tropical community tank, so water temperature and pH are rarely the deciding factor. Light, CO₂ and the look you want matter much more.

Lighting and CO₂: The Biggest Difference

Carpet plants live at the very bottom of the tank, which is the dimmest spot. That's why light is the number one thing to get right with either plant.

Monte Carlo wants moderate to high light, and it does best with CO₂. Without enough light, the stems start reaching upward instead of spreading sideways, and the carpet can lift off the substrate.

Dwarf Hair Grass also needs moderate to strong light, but it can be grown without CO₂. It will spread more slowly in a low-tech tank, so patience is part of the deal. In weaker light, the blades grow taller and thinner.

Pro Tip: If you don't run CO₂, Dwarf Hair Grass is usually the more forgiving pick. If you already have a strong planted-tank light and CO₂, Monte Carlo can fill in beautifully and fast.

Whichever you choose, keep your light on a steady daily schedule with a timer. Consistency helps carpets grow evenly and keeps algae from getting a head start, which matters even more in winter when room temperatures and daylight swing around.

How Each One Spreads (and How Fast)

Both plants are listed as fast growers, but they fill space in different ways.

Monte Carlo creeps outward, with each stem rooting as it goes. When it's happy, it knits into a dense mat that hides the substrate completely.

Dwarf Hair Grass sends runners under the substrate, and new blades pop up a short distance away from the parent clump. Over a few weeks, those little tufts connect into a lawn.

Don't worry if nothing seems to happen in the first week or two. New plants often spend that time settling in and growing roots before they start spreading. That's normal.

Planting Tips for a Carpet That Fills In

The way you plant makes a huge difference with both of these.

• Split it up. Monte Carlo arrives as a pot, and Dwarf Hair Grass arrives as a clump. Gently tease each one into small portions instead of planting one big chunk.
• Space the pieces out. Plant the small portions a little apart across the foreground. Each one becomes a starting point for the carpet.
• Bury the roots, not the leaves. Push just the roots into the substrate so the green parts stay above it.
• Use tweezers. A pair of curved aquarium plant tweezers makes it much easier to plant tiny pieces without them floating away.
• Feed the roots. Both plants pull nutrients from the substrate, so root tabs and a liquid fertilizer help them spread.

Struggling with hair grass specifically? Our guide to the 5 mistakes that kill Dwarf Hair Grass covers the most common problems.

Which Tanks Suit Each Plant?

Choose Monte Carlo if:

• You want a short, dense, bright green cushion.
• You have a strong light and run CO₂ (or plan to).
• You have a nano or shallow tank where a low carpet keeps everything in proportion.

Choose Dwarf Hair Grass if:

• You love the look of a natural grassy lawn.
• You run a low-tech tank without CO₂ and don't mind a slower fill-in.
• You keep shrimp or small fish that like to forage and hide in the blades.

Not sure your tank has strong enough light for either? A good rule of thumb: if your other plants grow slowly or stretch toward the surface, light is probably on the low side. Fix that first, then add your carpet.

Can You Grow Both Together? 🌱

Yes, and it can look fantastic. Many aquascapers mix the two to create a more natural foreground.

Try planting Monte Carlo right up front where its low cushion won't block the view. Then add Dwarf Hair Grass a little farther back, around rocks or along the base of driftwood, where its taller blades add texture and depth.

Give both the same care: steady light, root tabs, regular liquid fertilizer and a trim when they get too tall. Trimming the tops encourages both plants to grow thicker instead of taller.

Pro Tip: Leave a little gap between the two plants when you start. As they spread toward each other, the edge where they meet looks more natural than a hard line.

Ready to Grow Your Carpet?

There's no wrong answer here. Monte Carlo gives you a dense, leafy cushion that shines in bright, CO₂-fed tanks. Dwarf Hair Grass gives you an easygoing grassy lawn that's happy in more setups. And if you can't decide, plant both.

Start with a few pots or clumps, plant them in small pieces, keep your light steady and feed the roots. In a few weeks, you'll watch bare substrate turn into a green carpet.

Shop Monte Carlo →

Shop Dwarf Hair Grass →

Happy Planting! 🌿

The Marcus Fish Tanks Team