Marsilea crenata (Semanggi Air): A Gentle Clover-Like Groundcover

When people in Indonesia hear semanggi, many will remember the famous semanggi Surabaya dish – clover-like leaves served with warm, nutty sauce.

In the aquarium world, the same plant, Marsilea crenata, becomes a gentle, low-growing groundcover with tiny “clover” leaves that sway softly in the water.

In this post, I’ll share how I see semanggi air as both a familiar local plant and a simple, forgiving option for a natural-looking foreground in our tanks.

You can also browse my full plant list here: Aquarium Plants Simple Guide.

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Quick Profile

• Name: Marsilea crenata

• Common name: Semanggi air

• Type: Low-growing groundcover / foreground plant

• Family: Fern (not a true clover)

• Origin: Wet fields, ditches, and shallow waters in Southeast Asia

• Growth rate: Slow–moderate

• Difficulty: Easy–medium

Marsilea crenata can grow emersed (leaves above water) or submerged (fully underwater). In the wild, it’s used to changing water levels, which is why it can adapt quite well to aquarium life if we give it time.

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What Makes Semanggi Air Interesting in an Aquarium?

A few things I personally like:

• The leaves look like tiny clovers, which gives a calm, natural feel.

• It doesn’t demand extreme care or super strong light.

• It spreads by runners, slowly filling empty spaces between rocks and wood.

• It’s a plant with local roots – literally – so it feels familiar if you’re from Indonesia.

Before I commit to a carpet, I like to map the layout first, and this approach helps me keep things simple. Planning my aquascape on paper first

Compared to more “famous” carpet plants like Monte Carlo or HC Cuba, Marsilea crenata is slower, but it often feels more forgiving and less dramatic when something goes slightly off.

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Tank Size and Basic Conditions

Semanggi air doesn’t need a big tank. It works in:

• Nano aquariums as a soft foreground

• Medium tanks as a groundcover around rocks, wood, and paths

General water parameters (flexible ranges):

• Temperature: 22–28°C

• pH: around 6.0–7.5

• GH: Soft to medium-hard

• KH: Low–medium

If your tap water is similar to many parts of Indonesia or Malaysia – slightly hard, sometimes a bit alkaline – Marsilea crenata usually still adapts. Like most plants, it cares more about stability than perfect numbers.

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Light Requirements: Slow but Steady

Semanggi air will grow under:

• Low–medium light:

  • Growth is slow

  • Leaves may be a bit taller and more spaced out

  • Good for those who prefer low-maintenance tanks

• Medium–high light:

  • Leaves stay more compact

  • Runners spread faster

  • Higher chance of algae if nutrients and maintenance are not balanced

For a realistic home setup:

• Aim for medium light, around 6–8 hours per day to start.

• If algae appears, reduce the photoperiod or intensity slowly instead of making big sudden changes.

Because it’s a fern-type plant, Marsilea crenata doesn’t need “crazy” light to survive, but it will reward you quietly when light is stable and not too extreme.

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Do We Need CO₂ for Marsilea Crenata?

You can grow semanggi air with or without CO₂ injection.

With CO₂

• Runners spread faster

• Leaves often look more compact and fresh

• Overall carpet fills in more quickly

Without CO₂

• Still possible, especially in shallow tanks

• Growth will be slower

• Leaves may grow a bit taller

• Needs a decent substrate and patient care

If you’re not using CO₂:

• Keep the tank not too tall so light can reach the bottom.

• Use nutrient-rich substrate or root tabs.

• Avoid very long photoperiods (start from 6 hours).

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Substrate and Nutrients

Marsilea crenata uses both roots and leaves to take in nutrients.

You have two common options:

1. Aquasoil or Nutrient-Rich Substrate

• Plant directly into aquasoil.

• The roots will dig in and spread through the soil.

• Usually no need for root tabs in the beginning.

• Later, you can add a gentle liquid fertilizer if the tank seems nutrient-poor.

2. Sand/Gravel + Root Tabs

If you like the look of sand or fine gravel:

• Place root tabs in the area where you want semanggi air to grow.

• Keep tabs a few centimeters apart under the surface.

• Cover with a thin layer of sand/gravel so runners can anchor easily.

Try not to move the substrate too much once the plant is in. Runners slowly weave through the layer, and constant disturbance can slow growth.

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How I Plant Marsilea Crenata

You might get it in bunches, pots, or even as small clumps collected from shallow water or ponds.

Step 1 – Prepare the Plant

• Rinse the plant gently in clean water to remove mud or gel.

• Separate it into small clumps with a few leaves and roots each.

Step 2 – Prepare the Foreground

• Smooth out the area where you plan to plant it.

• Avoid steep slopes that might cause the plant to float up when filling with water.

If you prefer an even slower, tidy foreground plant, Cryptocoryne parva is another gentle option I rely on.

Step 3 – Planting

• Use planting tweezers if you have them.

• Push each clump into the substrate so the roots are buried and the leaves are just above the surface.

• Space the clumps a few centimeters apart – runners will fill the gaps over time.

Step 4 – Filling With Water

• If you’re setting up from dry start or empty tank, fill water slowly over a plate or plastic sheet.

• Replant any clumps that float up in the first few days. This is normal.

If you want a more playful creeping shape with faster coverage, Hydrocotyle tripartita ‘Japan’ is worth considering.

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Emersed vs Submerged Leaves: The Change Phase

Semanggi air often looks different when grown emersed compared to submerged:

• Emersed leaves (grown out of water) may be larger and thicker.

• After submerging, some of these old leaves may yellow or melt.

• New submerged leaves appear that are smaller, softer, and better suited to underwater life.

So if you see some melting early on, don’t panic immediately. Watch for new shoots and fresh, small leaves – that’s the real sign of adaptation.

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Trimming and Long-Term Maintenance

Marsilea crenata is not as demanding to trim as fast-growing carpets, but it still benefits from gentle maintenance.

When to Trim

• When leaves start to form a thick layer on top of each other.

• When the foreground looks messy, with some old, yellowed leaves.

How to Trim

• Use small scissors to cut leaves above the substrate level.

• Remove trimmed pieces with a net or during water changes so they don’t rot inside the carpet.

• Avoid cutting everything extremely short in one go if the plant is still young – leave enough healthy leaves so it can recover.

Over time, if the bottom layer becomes very old and brown, you can thin the carpet, remove some of the old clumps, and replant fresh runners for a cleaner look.

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Common Problems and Gentle Fixes

1. Very Slow or No Spreading

Possible causes:

• Light too low

• Very poor substrate

• Plant is still adapting from emersed to submerged

What can help:

• Check that light actually reaches the bottom (not blocked by floating plants).

• Add root tabs or a gentle liquid fertilizer if nutrients are lacking.

• Give it several weeks to adjust before making big changes.

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2. Yellow or Transparent Leaves

Possible causes:

• Nutrient deficiency

• Old emersed leaves dying off

• Plant is still new and adjusting

What can help:

• Trim off leaves that are clearly dying.

• Add a balanced fertilizer at a low dose if the tank is very lightly stocked.

• Monitor new leaves – if they come out healthy, the plant is fine.

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3. Algae on Leaves

Possible causes:

• Too much light for current nutrient/CO₂ levels

• Dirty foreground – waste settling between leaves

• Irregular water changes

What can help:

• Shorten lighting duration slightly.

• Gently vacuum above the carpet area during water changes.

• Keep feeding moderate so leftover food doesn’t sit among the leaves.

• Add algae-eaters that match your stocking plan (snails, small fish) if suitable.

Avoid harsh chemical treatments on this plant, especially if the tank has shrimp or sensitive fish.

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Is Marsilea Crenata Shrimp and Fish Safe?

Yes, semanggi air is safe for shrimp and most small community fish when not treated with chemicals.

Benefits:

• Shrimp enjoy picking biofilm off the leaves and stems.

• Fry and small fish can hide between the low foliage.

• The plant helps use up some nutrients and offers extra surface area for beneficial bacteria.

Just like with any low-growing plant, be mindful of debris and uneaten food getting trapped in the carpet. Light, regular maintenance helps keep the area healthy for everyone.

If you’re building a calm shrimp setup, this style of planting fits nicely with natural Neocaridina tanks.

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How I Like to Use Semanggi Air in Layouts

A few simple ideas:

• As a natural foreground below taller stem plants or swords.

• Around the base of driftwood or rocks to soften hard lines.

• Mixed with patches of sand or different plants to create a more “wild” look, like a shallow riverbank or paddy edge.

You don’t have to aim for a full, perfect carpet. Even scattered clumps of semanggi air can give a quiet, local, earthy feeling to the tank – like bringing a small piece of wet field into glass.

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Closing Thoughts: A Familiar Leaf in a Glass World

For me, Marsilea crenata is more than just a foreground plant.
It’s a reminder that many of the plants we eat, walk past, or see in our rice fields can live another life underwater – slower, softer, but still very much alive.

If you like the idea of a calm, steady aquarium instead of a fast, high-tech race, semanggi air fits that rhythm well. It grows at its own pace, and asks us to grow a bit of patience alongside it.

Next gentle reads:

– Cryptocoryne parva

– Hydrocotyle tripartita ‘Japan’

– Aquarium moss as a soft background player

– Aquarium Plants Simple Guide