Dwarf water lettuce is a popular plant choice for aquariums. It looks great, is easy to take care of, and can be used in a variety of different tanks.
This guide will cover everything you need to know about this plant. From benefits to maintenance, we have you covered!
Table of Contents
Dwarf water lettuce (Pistia stratiotes) is an herbaceous perennial plant that thrives in tropical and subtropical climates. The plant was first discovered along the Nile River, leading to its affectionate nickname of the “Nile Plant.” However, it’s quite abundant all over the world!
As you can guess from its name, this plant is a smaller variety of water lettuce. Larger specimens typically grow in massive lakes or near open river banks. Dwarf cultivars like this one, however, do very well in small aquariums and ponds.
Author Note: It’s a favorite among aquarists looking to infuse some life into an enclosed habitat. These plants offer tons of benefits and can quickly become the foundation of an environment teeming with life!
The Benefits Of Having It In Your Aquarium
You have a lot to gain from planting dwarf water lettuce.
The first perk you’ll notice is shelter. Water lettuce is a floating plant that sits on the water’s surface. As it grows, it continues to provide more and more cover from heat and light.
Not only that, but the roots extend pretty deep into the water. They fall down into the water column, creating a curtain of soft tendrils for fish and inverts to move through. Smaller creatures, such as fish fry, can use the plant as a hiding spot against would-be predators!
You may even notice direct changes in the overall water quality. Like all aquatic plants, dwarf water lettuce pulls nutrients from the environment to flourish. In an enclosed habitat like an aquarium, the plant can deprive algae of its fuel. As a result, you’ll have a cleaner tank that’s less prone to algae accumulation.
It takes harmful toxins as well! This plant will absorb ammonia and nitrates as it grows, which come from plant and animal waste. At exceptionally high levels, they will make the environment unlivable.
Author Note: While you still need a filter to take care of those chemicals, dwarf water lettuce will do a lot of heavy lifting! It removes the gunk and absorbs the waste while paving the way for healthy microorganisms to thrive.
When healthy and prospering, dwarf water lettuce is a sight to behold. It floats on the water’s surface in small florets. At first glance, mature plants look very similar to the lettuce or cabbage heads you eat!.
The gorgeous florets are made out of stocky leaves. Each leaf is wavy and features a distinct ridge pattern. They’re also thick and covered with fine hairs! You can feel a distinctively fuzzy texture when you touch them.
As the lettuce grows older, you might see small flowers form in the center of the floret. If you’re lucky, you may even see tiny red berries.
Underneath the plant, long white and black roots fall down the water column. They are pretty delicate and stringy, which might make it challenging for bigger fish to swim through. However, smaller creatures will enjoy the protection and cover the roots offer.
Size & Growth Rate
Dwarf water lettuce is a fast-growing plant. However, it’s not as fast as some other aquatic species out there.
The growth rate can still catch many by surprise, as the lettuce will quickly propagate and cover the surface if you’re not careful. That said, those who know what to expect can keep the spread under control (this is an important part of dwarf water lettuce care).
In the wild, the florets of the dwarf water lettuce can get as big as 10 inches wide! If the water is completely still, it may get even bigger than that!
Thankfully, things are a little different in closed aquariums! Captive growing environments typically stunt the size, stopping its growth once it reaches about four inches in diameter.
Dwarf Water Lettuce Care
As far as difficulty goes, dwarf water lettuce care is best classified as moderate.
It’s not particularly difficult to cultivate, but it’s not a walk in the park either! This plant does have some specific growing conditions. If things are just right, it’ll flourish without much intervention on your end.
However, getting the plant established is the tricky part!
Thanks to its relatively small size, dwarf water lettuce doesn’t need an enormous tank to thrive. At the very least, we recommend growing it in an aquarium that holds no less than 10 gallons.
Anything smaller may create some unnecessary challenges. This is especially true if you plan on adding aquatic animals into the mix.
Author Note: The main reason we recommend a 10-gallon aquarium (or larger) is because it will accommodate the lengthy roots and the moderate growth rate.
Dwarf water lettuce tolerates a generous spectrum of conditions. However, it’s not a fan of cold weather!
These plants do best in tropical environments. Most won’t even grow at all once temperatures dip into the upper 60s! They also like to have high humidity levels to support the leaves on top of the water.
Here are a few basic parameters to follow. Test your water conditions regularly to ensure that you’re meeting the plant’s needs. While dwarf water lettuce care is fairly straightforward, this is an area you’ll want to pay close attention to.
- Water temperature: 72°F to 86°F
- pH levels: 6.0 to 7.5
- Water hardness: Around 4 to 5 dKH (soft to medium-hard)
Contrary to popular belief, dwarf water lettuce doesn’t need direct sunlight around the clock to stay healthy. In fact, too much sun could be a big problem!
These plants prefer to live in slightly shady environments. They still need a reasonable amount of sun that revolves around a standard day/night cycle, but try to keep the lighting levels moderate.
Author Note: Never apply direct light to the leaves. Excessive exposure can lead to scorching and yellowing!
Use small, full-range bulbs. Keep the lights on throughout the day, and don’t keep them too close to the water’s surface. If possible, consider placing your aquarium near an open window! The residual lighting should be more than enough to help those lettuce florets reach their full potential.
As you may have guessed, choosing the right substrate choice for dwarf water lettuce isn’t something you have to worry about!
These plants float on the water’s surface and don’t have roots that anchor them down. The roots are free-floating in the water, so your choice of the substrate material won’t have a direct impact on the health of this plant at all.
Instead, focus on choosing a substrate that complements the needs of the other plants or animals in the aquarium.
How To Plant It
Getting the water and environmental conditions right is only half the battle. Once your tank is correctly set up and cycled, you can start thinking about adding your plant.
Dwarf water lettuce is readily available online and from pet stores. Introducing the plant to your tank is as easy as gently placing the roots into the water and floating the existing leaves on the surface.
But before you do that, it’s important that you quarantine the plant!
Like new fish and inverts, water lettuce can carry diseases and parasites. The last thing you want to do is infest your tank with dangerous hitchhikers. Give the plant some time in a quarantine tank to ensure that it’s not harboring any invaders.
Author Note: Make the conditions of the quarantine tank identical to the main tank. Doing so will make the transition period much easier.
After adding the plant to the primary aquarium, keep a watchful eye on it. Some plants may shed their roots or become discolored. Root shedding is normal. It’s a byproduct of stress, and the roots will grow back in no time.
However, discoloration is a sign of improper lighting. Yellowing is typically a sign of too much direct sun, so make adjustments as needed.
Never submerge the leaves or floret. Doing so could cause rot and fungal problems. Interestingly enough, the dwarf water lettuce leaves are water-phobic. The finish ensures that water slides right off, making it nearly impossible to sink the plant!
It’s also a good idea to adjust water flow and filtration. Despite the plant’s ability to clean the tank, you still need a filter to keep the tank in good shape. However, you must set the filter to work in the plant’s favor.
Dwarf water lettuce doesn’t like too much movement in the water. A strong water flow will stunt its growth. Keep things light and make sure that there are no strong currents from the filter outlet directed at the plant’s root.
Trimming & Pruning
Regular pruning is a very important part of dwarf water lettuce care. Once the plant reaches maturity, you may need to start trimming it on a weekly basis to prevent overgrowth. If you don’t, the plant will quickly spread to cover the entire surface.
To trim the plant, just pinch off plantlets. Those are the tiny leaves that start to form in the center. Pinch them off with your finger or use some pruning shears.
You can also cut off some of the roots. The roots will continue to grow in the water as the leaves on the top spread. If they start to get unruly, use some scissors to shorten them. Leave behind about four inches.
Author Note: Don’t worry, the plant will recover. Trimming the roots may actually help improve the plant’s overall health. Cutting them back leaves fewer tendrils for the lettuce to expend energy maintaining.
Dwarf water lettuce plants are beautiful above and below the waterline. Proper lighting highlights the thin and delicate nature of the roots.
When you see them, you’ll notice that the roots are quite dense. For this reason, not all fish are going to do well with dwarf water lettuce plants in the mix.
The roots are too much for larger fish. Do not pair these plants with fast-moving fish or those with long and flowing fins. The former will only tear the roots up and destroy the plant. Meanwhile, the latter will get caught up in the net of roots and succumb to stress-related issues.
Your best bet is to pair these plants with small fish and invertebrates.
Shrimp adore the dense root system of dwarf water lettuce plants. The same goes for crayfish and crabs!
Usually, crayfish and crabs cannot live with plants because they have a penchant for tearing the roots up with their claws. That’s not a problem with floating plants like dwarf water lettuce.
As a general rule of thumb, avoid large fish, weak swimmers, or any species that likes to snack on plants. Here’s a good list of the best dwarf water lettuce tank mates to consider:
- Freshwater crab
- Nerite snail
- Malaysian Trumpet snail
- Mystery snail
- Ramshorn snail
- Cherry shrimp
- Ghost shrimp
- Amano shrimp
Dwarf water lettuce is a unique plant. It can spread in a couple of different ways. In the wild, it will propagate sexually. Male and female flowers can fertilize, resulting in berries and seeds.
The process is pretty similar to what you would see on land-based plants.
While it is possible to replicate those conditions in a home aquarium, it’s not very common. Typically, dwarf water lettuce will propagate asexually in closed tanks.
When this happens, the plant will spread using stolons. Also known as runners, stolons are horizontal stems or roots. They grow beneath the water, sprouting new plants at various nodes along the length.
Small “daughter” plants will appear next to the central plant. They look like small florets and will continue to grow into adult plants if you give them a chance.
Author Note: If you don’t intervene with trimming and pruning, this propagation method will go on until you have a thick carpet of stolon roots. Before you know it, the cabbage will cover the entire surface of the water!
Now, it’s entirely up to you to decide how much you want the plant to spread. When you notice a daughter plant appearing, you can snip the stolon and dispose of it. Alternatively, you can move it to another tank to start a brand-new plant!
The choice is yours. Propagating dwarf water lettuce is a breeze. It’s only a matter of time before the stolons form new plants.
Once you get the hang of it, dwarf water lettuce care shouldn’t prove to be very difficult. The benefits and aesthetic appeal of this plant make it a worthy inclusion for just about any aquarium (depending on the occupants of course), and we highly recommend it!
We’d love to hear your thoughts and feedback on this guide. We’re always looking to improve and provide the most useful information possible!