Quick answer: Moneywort (Bacopa monnieri) is one of the easiest stem plants you can grow. It has upright stems lined with small, bright green rounded leaves, it does not need CO2, and it grows in almost any tank with basic lighting. It sits best in the middle or background and reaches about 12 inches tall, sometimes more. The one thing most listings leave out: moneywort is usually grown above water before it is sold, so it often drops its lower leaves or looks rough for a couple of weeks after you plant it. That is normal, not a sign you killed it. Give it time and it grows back adapted to life underwater.
Moneywort vs creeping Jenny: which plant do you actually have
This trips up a lot of people, so let us clear it up first.
In the aquarium hobby, moneywort almost always means Bacopa monnieri. That is the plant this guide is about. It is a soft stem plant that grows underwater and is sold in bunches or pots at fish stores. You may also see it labelled water hyssop or brahmi, which are its non-aquarium common names.
There is a completely different plant also called moneywort, and that one is creeping Jenny (Lysimachia nummularia). Creeping Jenny is a low garden groundcover with round, coin shaped leaves. It is not an aquarium plant, and in some parts of the United States it is treated as invasive in gardens and wild areas.
If a search result shows a plant creeping across soil in a yard, that is creeping Jenny, not the aquarium plant.
Simple rule: if you want the plant for your fish tank, look for the name Bacopa monnieri on the label. That is your moneywort.
What moneywort looks like and how big it gets
Moneywort has thick, upright stems with pairs of small, rounded leaves growing opposite each other. The leaves are a light, almost lime green, which stands out nicely against darker plants. Each stem with its leaves is only about 2 inches wide, so it stays neat and does not sprawl sideways the way some plants do.
In a tank it usually grows to around 12 inches tall, though under strong light it can reach 20 inches or more. Once it hits the surface it keeps going sideways along the top of the water.
Because of that height, moneywort works as a middle or background plant. Plant a few stems together in a small group and they read as a soft green bunch rather than single lonely stems.
Moneywort care at a glance
None of these conditions are strict, which is part of why it is such a good beginner plant.
| Scientific name | Bacopa monnieri |
| Also sold as | Water hyssop, brahmi |
| Lighting | Low to high, medium to high keeps it bushy |
| Temperature | 68 to 82°F (20 to 28°C) |
| pH | Around 6.5 to 7.5, tolerates a little either side |
| Hardness | Soft to moderately hard |
| CO2 | Not required |
| Placement | Middle to background |
| Height | Around 12 inches, up to 20 in strong light |
| Growth rate | Moderate to fast, needs regular trimming |
| Difficulty | Easy |
Does moneywort need CO2 or fertiliser?
No, moneywort does not need CO2. This is one of its best features. In a tank with fish it can often feed on the waste already in the water and grow perfectly well with nothing added. Injected CO2 will make it grow faster and denser, but it is a bonus rather than a requirement.
Fertiliser is similar. In a lightly planted tank with fish, moneywort may grow fine on its own. In a heavily planted tank where many plants compete for food, it grows greener and fuller with a little help. A liquid fertiliser once or twice a week covers most tanks.
If your substrate is plain gravel or sand with no nutrients in it, a root tab tucked near the roots every month or so gives it something to feed on.
If the leaves start yellowing, that is usually a light or nutrient signal. Our guide to aquarium plant deficiency symptoms walks through how to read those signs.
Substrate, and how to plant it so it stops floating
Moneywort grows best rooted in a nutrient rich aquarium soil, but it is not picky. It will also grow in gravel or sand. The catch with gravel and sand is that they do not hold the stems well, so freshly planted moneywort loves to pop back up and float away before it roots.
Here is how to keep it down until it anchors itself:
- Bury the bottom 1 to 2 inches of each stem, deep enough to cover a node or two
- Use aquarium tweezers to push each stem in, which is far easier than fingers
- Space stems about 2 inches apart so light reaches all of them
- If they keep floating, weigh the base down with a small rock, a plant weight, or nearby decor
- Give it about a week, and the stems will send out white roots and hold themselves in place
Once it roots, it stays put and you can forget about the floating problem.
Moneywort in low light: the honest version
Most care guides tell you moneywort is a low light plant and stop there. That is only half true, and the half they skip is the part you actually need to know.
Moneywort survives in low light, yes. It will not die on you. But low light changes how it grows. Instead of staying short and bushy, the stems stretch and reach for the light, so you get long gaps between the leaf pairs and a leggy, thin look. The lower leaves, which sit in the most shade, often drop off, leaving bare stems at the bottom and a tuft of green up top.
So the honest version is this: moneywort tolerates low light, but it looks its best under medium to high light. If you are running a low tech, low light tank, moneywort still belongs on your list, just expect a taller, looser plant rather than a tidy green bunch.
If you want other plants that genuinely thrive in dim tanks, see our roundup of low light aquarium plants.
Why your moneywort is melting or dropping lower leaves
If you planted moneywort and it started shedding leaves or looking mushy within a couple of weeks, do not panic and do not throw it out. This is the most common moneywort problem, and it usually fixes itself.
Most moneywort is grown emersed, meaning above water at the farm, because it grows faster that way. The leaves it grows in the air are built for air. When you put those stems underwater, the old emersed leaves cannot cope, so they melt or fall off while the plant grows brand new leaves suited to life underwater. It looks alarming, but the plant is not dying. It is switching modes.
This is the same process that catches people out with Cryptocoryne, and it is worth understanding in general, since plant melt after planting affects most new plants to some degree.
What to do about it:
- Leave the stem in place even if it looks bare, since new growth comes from the top and the nodes
- Remove any fully mushy leaves so they do not rot in the water
- Keep your light and nutrients steady while it adjusts
- Wait two to four weeks, and you should see fresh, healthy leaves appear
If leaves keep dropping well after that adjustment period, look at light first, since too little causes lower leaf loss, and nutrients second.
How to trim and propagate moneywort
Moneywort grows quickly enough that trimming becomes part of owning it. The good news is that trimming and propagation are the same job, so every cut gives you a new plant for free.
To trim, cut the top few inches off a tall stem with clean scissors. The stem you cut from will often push out side shoots below the cut, which makes the original plant bushier over time.
To propagate, take that cut top, strip the lowest pair of leaves, and push the bare end into the substrate. It will root at the node and grow into a new stem. That is the whole process.
A few tips that help:
- Cut just below a leaf node, since roots form at the nodes
- Replant cuttings in small groups for a fuller look
- Trim before stems get too long and start shading their own lower leaves
- Clean scissors help avoid introducing rot into fresh cuts
Because it propagates this easily, a single bunch of moneywort can fill a background over a few months at no extra cost.
Growing moneywort floating or emersed
Moneywort does not have to be planted. It grows just as happily floating, and floating it is one of the easiest ways to grow it. Let a few stems drift and they will grow upward, break the surface, and keep going in the air. Floating stems give baby fish and shy fish a place to hide, and they root at the nodes as they go.
If moneywort grows out of the top of the water, it can also flower. The blooms are small and appear on the emersed part of the plant above the surface. You do not need the flowers to propagate, since cuttings do all the work, but they are a nice bonus if you let it grow tall and open.
This same amphibious habit is why moneywort works in paludariums, tanks that mix underwater and above water zones.
Tank mates: is moneywort safe with your fish?
Moneywort is safe with almost any community tank. The stems are sturdy for a soft plant, so it holds up better than delicate species around active fish. It suits tanks with tetras, rasboras, guppies, and other peaceful fish, and it makes good cover for fry.
If you are still choosing stock, our list of beginner aquarium fish pairs well with a moneywort background.
A couple of honest cautions. Large plant eaters such as goldfish or big cichlids may nibble or uproot it, so it is a better fit for community tanks than for dedicated goldfish setups.
Shrimp, on the other hand, love it. Amano shrimp and other algae grazers will pick biofilm off the stems without harming the plant at all.
Common moneywort problems
Most moneywort trouble traces back to three things: light, nutrients, or the plant still settling in after you planted it.
| Problem | Likely cause | What to do |
|---|---|---|
| Lower leaves falling off | Low light, or the switch from emersed to submersed | Raise light gradually and pull off any dead leaves |
| Leaves turning yellow | Too little light or nutrients | Check lighting first, then add liquid fertiliser or a root tab |
| Leaves turning brown | Usually a brown algae film in a new tank, or old leaves dying back | Wipe or trim the affected leaves; brown diatom algae fades as the tank matures |
| Leggy stems with big gaps between leaves | Not enough light, so the stems stretch to reach it | Increase light intensity or hours, going slowly to avoid an algae bloom |
| Melting soon after planting | The normal emersed to submersed transition | Remove mushy leaves and wait two to four weeks for new growth |
| Barely growing | Still adjusting after planting, or low light and nutrients | Give it a few weeks, then improve light and start dosing |
| Stems floating up | Not rooted in yet | Replant deeper and weigh them down until roots form |
Moneywort FAQ
Is moneywort the same as creeping Jenny? No. Aquarium moneywort is Bacopa monnieri, an underwater stem plant. Creeping Jenny is Lysimachia nummularia, a land groundcover. They share a common name but are different plants.
Can moneywort grow in gravel? Yes, though gravel does not hold nutrients, so add a root tab nearby. Gravel is also looser, so the stems may float until they root. Bury them deep and weigh them down for the first week.
Does moneywort need substrate? No. It grows planted in substrate, floating at the surface, or emersed in a paludarium. Substrate helps it root and feed, but it is not required.
Can moneywort grow out of water? Yes. It is an amphibious wetland plant. It grows underwater, floating up out of the surface, or fully emersed above the waterline, and it flowers when grown in the air.
How fast does moneywort grow? Moderate to fast, and noticeably faster under strong light or with added CO2. Plan on regular trimming to keep it neat.
Does moneywort need CO2? No. It grows well without CO2 injection, which is part of why it suits low tech tanks. CO2 speeds growth but is not required.
Why is my moneywort leggy? Almost always low light. The stems stretch toward the light, leaving long gaps between leaf pairs and often shedding the lowest leaves. More light keeps it compact.
Is moneywort invasive? The aquarium plant, Bacopa monnieri, is not the invasive garden groundcover people worry about, that is creeping Jenny. Still, never release any aquarium plant into local waterways. Bin trimmings you do not want.
Final word
Moneywort earns its spot as a beginner favourite. It is cheap, hardy, easy to multiply, and forgiving of the mistakes new tanks come with.
Plant it, give it a couple of weeks to settle in, trim it when it gets tall, and it will fill your background with soft green for as long as you keep the tank running.
Just go in knowing two things. It will look rough for the first fortnight while it adapts to being underwater, and in low light it grows tall and leggy rather than bushy. Neither is a failure. Both are just the plant behaving normally.
About the author: Aqua Planet is a planted tank site focused on honest, hands-on troubleshooting and beginner-friendly aquarium care. You can see the tanks and setups behind these guides on the Aqua Planet YouTube channel.
