Monte Carlo Complete Growing Guide 2022 (growing, feeding, trimming)

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Monte Carlo (more properly called Micranthemum ‘Monte Carlo’) is one of the easiest carpeting aquarium plants to grow across the aquarium floor. This plant is famed for being used by professional aquascapers to create lush, green carpets in their displays.

Monte Carlo is a surprisingly undemanding plant that will quickly spread across the bottom of your fish tank providing it is supplied with medium to high light and given a good quality aquarium fertilizer.

Whether you are new to aquarium plants, or well on your way to being a professional aquascaper, Monte Carlo will no doubt enhance your aquarium.

Overview of Micranthemum ‘Monte Carlo’

Anyone who has had even moderate success creating a carpet with Monte Carlo will tell you how amazing this plant looks. With its small, bright green leaves and natural spreading habit, Monte Carlo makes a lush green carpet with little effort.

Micranthemum ‘Monte Carlo’ is named after the village of Montecarlo, in Argentina which is where the plant was first discovered.

Monte Carlo is a relative newcomer to the aquarium hobby. It was only introduced around 15 years ago.

Monte Carlo grows away quite happily in the aquarium, slowly creeping forward to create a soft pillow of small rounded leaves. The resulting carpet provides the perfect place for baby Red Cherry Shrimp and other tiny aquarium inhabitants to live.

Monte Carlo Characteristics

Common Name:Monte Carlo, Bacopita, New Large Pearl Grass, Montecarlo pearlweed, and Tweedie’s pearlweed
Scientific Name:Micranthemum tweediei
Care Level:Easy to moderate
Growth Rate:Moderate
Light Level:Medium to High
C02 Level:Medium
Tank Location:Foreground
Temperature:72°F – 78°F (22°C – 25.5°C)
Color:Bright green
Propagation Method:Division
Maximum Height:2″ – 4″ (5 – 10cm)
Minimum Tank Size:5-gallons (19 liters)

Monte Carlo Origins

It is widely reported that Micranthemum ‘Monte Carlo’ gained its popular common name thanks to the village in Northern Argentina where it was first discovered.

In the wild, Monte Carlo grows in shallow rivers and streams, where it is most likely to be found in slower sections of the water coarse. Monte Calo can also be found growing up river banks.

In January 2013 a sample of Monte Carlo was sent to Tropica, one of the worlds leading plant breeders and suppliers. There they ran extensive testing, growing it in their laboratory alongside other, similar plants including Hemianthus callitrichoides ‘Cuba’, Micranthemum umbrosum, and Glossostigma elatinoides. They discovered Monte Carlo grew well and was actually easier to grow and more adaptable than other, similar carpeting plants.

In 2017, Monte Carlo was officially described by Christel Kasselmann. It was given the scientific name Micranthemum tweediei

Micranthemum ‘Monte Carlo’ General Description

Monte Carlo is often described as a carpeting plant. This description comes thanks to Monte Carlo’s desire to creep along the aquarium floor, putting down roots constantly as it moves.

Monte Carlo does not grow very tall, reaching only 2″ to 4″ (5cm to 10cm) above the substrate.

This plant has thin, bright green stems that radiate vertically along the ground. Everywhere the stems touch the substrate they will sprout roots, adding to the carpet effect of the plant. Every few millimeters along the stems, a pair of rounded, bright green leaves will sprout.

Ideal Tank Conditions for Monte Carlo

Despite what others might have you believe, Monte Carlo is actually a fairly easy carpeting plant to grow. Providing you give it plenty of light and dose with fertilizer on a regular basis, Monte Carlo should reward you will a lush, green carpet of leaves.

I currently grow Monte Carlo in a variety of tanks, and the conditions do vary, but the plant still grows well. I have found substrate to be an important consideration.

Because of the way Monte Carlo grows, creeping along and anchoring itself at regular intervals, it needs a substrate that can hold it in place. I have found aquarium sand to be a poor choice of substrate for Monte Carlo. In my experience, it never seems to get a proper grip and keeps floating up in sections.

Fluval Stratum on the other hand, although very light in weight, seems to work really well for Monte Carlo.

I have also had good success growing Monte Carlo in aquariums with fine aquarium gravel. Again the plant seems to be able to get a good hold on the substrate and stay fastened to the bottom of the tank.

Light is probably the main determining factor as to whether or not Monte Carlo grows well in your aquarium. This is a plant that requires moderate to high light to grow well. In fact, the brighter the light, the lower and more compact Monte Carlo will grow.

I have found that the Fluval Plant 3.0 LED light gives you the best bang for your buck when it comes to growing Monte Carlo, although there are more expensive lights out there that will do the same job. I have also had some success growing Monte Carlo using the Fluval Aquasky light, although the plant does appear to stretch for the light a little more with the Aquasky.

Monte Carlo is a plant that requires a decent amount of aquarium fertilizer to grow well. I use a liquid fertilizer in my tanks. I have found Easy Green, which is sold by Aquarium Co-op, to be the simplest fertilizer to feed my Monte Carlo as you only have to add a few squirts once a week to get good results.

There are other fertilizers that do the job too. I have tried many of them over the years, but none of them had the same effort/reward ratio as Easy Green does.

Monte Carlo is a plant that will definitely benefit from the addition of CO2. CO2 is usually added to aquariums using a gas canister filled with CO2, a regulator to control the amount of CO2 entering the tank, and a diffuser to physically add the CO2 to the aquarium.

Adding CO2 is more of an art than a science and requires a lot of ‘tinkering’ from the fish keeper to get the levels right. Too little CO2 and you will have no effect on your plants, too much and you will kill your fish.

In my experience, always start by adding very little CO2 to your Monte Carlo tank and monitor your plants. If growth is slower than expected, increase the CO2 SLIGHTLY, then monitor again. Continue with this process over several weeks until you get the balance right. When you get the balance spot on, your Monte Carlo will start to ‘pearl’.

Pearling is the name given when plants are so happy they are releasing small bubbles of oxygen into the aquarium. In the image below, which is taken from a YouTube video by Peminat Aquascape, small bubbles of oxygen can be seen sitting on the Monte Carlo carpet.

Maintaining Monte Carlo

When it comes to growing a really good carpet of Monte Carlo, there are two pieces of regular maintenance you will need to fit into your schedule.

  • Vacuuming
  • Trimming

Regular vacuuming

By the very nature of a carpet of plants running along the bottom of your aquarium, everything that falls down through your aquarium water will land and sit on your Monte Carlo carpet. Uneaten food, fish poop, and even molted skins from Red Cherry Shrimp.

When this debris lands on your Monte Carlo it may build up and cause your plants to rot, creating bare patches in your lush green carpet.

Vacuuming your Monte Carlo regularly, ideally when carrying out your normal water changes, will remove much of the debris and prevent sections of your plants from dying.

Regular trimming

If you have ever looked at a perfect carpet of Monte Carlo with envious eyes, wondering how they achieved the perfect green lawn in their aquarium, let me assure you the secret is regular trimming.

Really high-end aquascapers may trim their Monte Carlo every few days. It becomes an obbseisson.

Trimming Monte Carlo prevents it from becoming tall and leggy and encourages more, low-level growth. I have to be honest, I do not that have much commitment to my own Monte Carlo. Instead, I probably trim mine every 6 to 8 weeks.

Propagating Monte Carlo

Propagating Monte Carlo could not possibly be easier. All you need do is take any section of Monte Carlo and cut it into smaller pieces. Each small piece will have roots naturally due to the way Monte Carlo grows.

Once cut into small pieces, each piece can be planted individually, where it will quickly grow and begin to form a new carpet.

The only real consideration is how to keep small pieces of Monte Carlo attached to the substrate while it forms new anchor roots. I have found pushing it a little deeper into the substrate than you might want it, then waiting for it to grow out and along the floor to be the best method to get new, small pieces of Monte Carlo to stay in place.

What Fish Can be Housed with Monte Carlo?

One question I am often asked when giving fish and plant talks at aquarium clubs is ‘what fish can live with Monte Carlo?’. The answer is simply any fish that isn’t too boisterous.

In my own tanks that have Monte Carlo growing in them, I keep lots of Tetras like Neon Tetras, Cardinal Tetras, and Lemon Tetras. I also keep Angelfish, Dwarf Gouramis, Bolivian Rams, and Bettas.

I would avoid any large Cichlids like Oscars, Green Terrors, or Midas Cichlids and I would also avoid any known diggers. Members of the Geophagous family for example would quickly destroy a carpet of Monte Carlo.

One addition that is almost compulsory in tanks where Monte Carlo is growing is Red Cherry Shrimp. Red Cherry Shrimp will spend their entire day combing the Monte Carlo, looking for and removing uneaten fish food as well as breaking down fish poop.

Red Cherry Shrimp will also eat the starts of any algae they come across. One of the best steps anyone can take to stop algae from taking over their tanks is to get some good algae eaters, and Red Cherry Shrimps eat a lot of algae.

What Other Plants Can Be Grown With Monte Carlo?

To be fair, just about any other aquarium plants can be grown in the same tank as Monte Carlo, providing the other plant does not shade out the Monte Carlo. Monte Carlo needs the bright light to grow, and when other, taller plants grow over it, the Monte Carlo can die back very quickly.

In my opinion, Monte Carlo does best when grown in an open space in the aquarium.

Where to Buy Monte Carlo?

Monte Carlo is an easy plant to grow but is not stocked in as many stores as it should be. Any good local fish store that sells aquatic plants will almost certainly have Monte Carlo in stock. If not, or you don’t have a good local fish store where you live, try I have always found their plants to be top quality and their service is really good.

Common Problems with Monte Carlo

The biggest problem people have with their Monte Carlo is the bottom of the plant turning brown and rotting off. This happens them the carpet of Monte Carlo becomes so thick, that the light can not penetrate to the bottom of the plant, which then dies off.

The solution is trimming. Trimming your Monte Carlo more regularly will allow more light to penetrate right down to the base of the plant.

Another issue is raised nitrate levels. When the nitrate levels in the water become too high, the Monte Carlo can begin to melt away. Monte Carlo is not very tolerant of high nitrate levels.

If you are unsure of your water parameters, I strongly recommend getting yourself a Master Test Kit which is made by API.  The test kit is easy to use, fairly accurate, and doesn’t cost a great deal (check the latest price of an API Test Kit on

The third problem some Monte Carlo growers report is detachment. Detachment is when the roots fail to grip the substrate they are growing on. Most often this happened when the Monte Carlo is first planted.

The solution to detachment is to either push sections of the Monte Carlo gently into the substrate or consider using small, bent pieces of wire to hold the Monte Carlo in place until it forms good, strong anchor roots.

Frequently Asked Questions About Monte Carlo

Can Monte Carlo be grown as a floating plant?

No, Monte Carlo can not be grown as a floating plant. When Monte Carlo is allowed to float, three things will happen. Firstly, it will become a tangled mess of leaves and roots. Secondly, fish in the tank will constantly pick at it, which will result in it dying back before rotting away completely. Finally, when Monte Carlo is kept that close to the light, it will quickly become overgrown by algae, which will cause the Monte Carlo to die back.

Does Monte Carlo require CO2 to grow?

Whilst Monte Carlo does not strictly require CO2 to grow, in my experience, it grows a lot quicker and thicker when grown in an aquarium that has CO2 injected into it.

Is Monte Carlo easy to grow?

Monte Carlo is generally considered an easy to moderate plant to grow, and it is certainly the easiest of the carpeting plants to grow. Monte Carlo is recommended for those who have at least some experience in growing aquatic plants.

Can Monte Carlo grow in normal gravel?

Yes, Monte Carlo can be grown in regular aquarium gravel, providing the average stone size does not exceed 2-3mm. When the gravel is too large the Monte Carlo struggles to get a hold as it only has a small, shallow root system.

Can Monte Carlo grow in low light?

No, Monte Carlo needs at least a moderate to high light to grow. When grown under low light levels the plant will become leggy as it stretches up to reach the light. Monte Carlo grown under low light levels will turn brown and rot away.

Can Monte Carlo grow on rocks?

No, Monte Carlo won’t attach itself to rocks, wood, or decorations. The root system of Monte Carlo is designed to hold the plant in the substrate. Java Moss or Java Fern are better plants for fixing to rocks.

In Conclusion

Monte Carlo is a stunning plant that everyone should try at some point in their hobby. It is certainly the easiest of the carpeting plants to grow and providing you have at least a moderately good aquarium light, Monte Carlo will quickly form a thick carpet across the bottom of your aquarium.

As long as you trim your Monte Carlo when it grows too tall or thick, and you fertilize it regularly with a good quality aquarium fertilizer, Monte Carlo will help you create an aquascape that looks stunning for years.

About the Author

I’ve been keeping, breeding, and showing tropical fish for nearly 30 years. Over that time I’ve done it all! I’ve had great success and I’ve made some really foolish mistakes (like the time I bought an Asain Walking Catfish). Read more…
Richard James

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