The Ultimate Care Guide To Dwarf Water Lettuce

Water lettuce is an aquatic plant in the Hydrocharitaceae family. Like many aquatic plants, water lettuce can be an exciting and beneficial addition to your aquarium.

Aquarium plant growers sometimes refer to this curious floating plant as duckweed or frogbit, but true water lettuces are not closely related! I thought it would be interesting to write about this plant because many people are unaware of its existence, and I think most will agree that looking at the unique structures on the leaf is quite remarkable!

In this article, we will cover everything you should know about the dwarf water lettuce.

Dwarf Water Lettuce: Species Summary

Common Name:	Water Lettuce
Scientific Name:	Pistia stratiotes
Origin:	South America, Africa, Australia
Size:	Varies by species, typically around 1 foot
Lighting:	Moderate to high
Temperature Range:	72°F to 86°F
pH range:	6.0 to 7.5
Tank size:	10 gallons
Care Level:	Easy to Moderate
Diet:	Omnivore

The leaves of water lettuce are long, oval-shaped structures that protrude from a central “stem” like structure. When the leaf is not floating, it appears to be rolled into a somewhat cylindrical bead.

On the underside of the leaf, there are often hundreds if not thousands of tiny “hairs” called trichomes. These trichomes give the leaf a fuzzy look and can also trap air bubbles, allowing them to float.

This plant is an annual to perennial, meaning in its native environment, it grows for part of the year. Then it goes dormant when water conditions become unfavorable (typically during dry months). They may grow year-round in a nonnative environment such as a planted aquarium.

This is a floating aquatic plant which means in its natural environment, the fragile floating leaves would not survive under the water’s surface. You can place them in several ways in a planted aquarium to show off their exciting structures.

Some people plant them near the substrate level, where they will eventually rot and add nutrients to your soil.

Water lettuce grows in many areas worldwide but will not grow in colder climates. They prefer warm and tropical climates.

This floating plant can grow in shallow water, such as swamps and marshes, or live in deeper waters up to six feet deep.

This is an excellent oxygenator for smaller aquariums, especially when you have fish that may get scared of large, fast-moving plants.

It can be used as a canopy or carpeting plant in smaller tanks. This plant does not need to be planted and never needs trimming, so it is a very low-maintenance addition to your aquarium.

Dwarf Water Lettuce: Appearance

Pistia stratiotes appear to look a lot like a miniature version of duckweed. The plant is identified by its round leaves that have long stalks coming from the center. Some varieties have dark green leaves, while others have brownish-green ones. Despite popular belief, this plant does not resemble water lettuce.

The leaves of this plant are a medium to dark glossy green, with the underside being a pale yellow. There are two different leaf shapes, one which is ovate and slightly curved inward and the other which is more flat.

Water lettuce looks best when planted in large groups. These plants love nutrient-rich water, so heavy fertilizing is recommended for optimal growth. They can also be planted in small groups or even singularly, but they look their best when allowed to grow unhindered.

Dwarf Water Lettuce: Size And Growth Rate

This plant only grows to be about 10 inches wide. If you do not disturb the plant, it can grow indefinitely and becomes a thick mat across the top of your aquarium (over time).

Water lettuce will float on and slightly above the surface of your water or root in the substrate. When this happens, it signifies that the plant is ready to reproduce.

In its natural environment, it reproduces through a flowering stem that grows up from the center of the rosette and eventually produces flowers at the top.

This plant has the potential to grow up to several feet wide in a single season if conditions are right. It can also quickly colonize an entire tank in no time flat. This makes it perfect for decorating your aquarium, but it may seem invasive or out of place if not managed carefully.

Other Species

This plant is readily available in various shapes, sizes, and colors. There are several varieties, including – Pistia stratiotes ‘Sagittata’ (Arrowhead), which has arrow-shaped leaves instead of oval or round ones. It can also come in a variety called ‘Tropica.’

This is a smaller and more compact plant with leaves that can grow as long as inches. – Limnanthemum indicum (Water Snowflake) has longer leaves than the stratiotes ssp.’Sagittata’ and is also shorter in height, usually not getting higher than 10-15 inches.

Its arrow-shaped leaf blades grow on short stalks that do not float. – Limnanthemum marginatum (Snowflake) is similar to the L. indicum, except it has incredibly long thin leaves that can be as long as a foot.

This variety spreads rapidly and is perfect for decorating the back area of your aquarium. – Limnanthemum nymphoides (Cuba Lily) has broader leaves than the other species and typically only grows about 8 inches tall. It can also root itself in the substrate but not as well as L. stratiotes ssp.’Sagittata.’

Difficulty Level

Water lettuce is a straightforward plant to grow and maintain. It requires little attention and can be left alone for weeks without trimming or pruning.

Water lettuce does not need substrate to root in and will reproduce readily if allowed. Water lettuce is not sensitive to ammonia, nitrites, or any measurable levels of nitrates.

When used in outdoor ponds, this plant can help clean up water by absorbing the nitrogen found in it naturally. While taking in these contaminants, the plants also produce oxygen. This makes it perfect for beginner aquarists, but ensure you provide plenty of space to grow.

Place your water lettuce away from any air conditioning vents or other sources of drafts. The plant can be damaged easily by cold gusts of wind, which will show stress if left in the open for too long.

Dwarf Water Lettuce: Reproduction And Propagation

Pistia stratiote is a straightforward plant to reproduce in an aquarium environment. It spreads rapidly by sending out runners in all directions and creating new plants, so keeping your eye on it is essential.

If you allow too much of this plant to spread through your tank, you will soon have little free space left.

It can reproduce by sending up a flowering stalk to produce flowers and fruit (seed pods). However, the most common way of reproduction is through offshoots that grow from the base of the plant.

These shoot up rapidly and, if not maintained, can overtake your tank in no time. Seeds require light to germinate, so it’s best to plant new shoots directly in your substrate.

Water lettuce reproduces both sexually and asexually. The flowers are tiny, typically less than 1mm in diameter, but they can be seen because of how reflective the petals are to light. These plants will occasionally flower in my aquarium when the day is 12+ hours long.

When it does, try to take a few stems and move them to other tanks for propagation.

• 3 Gallon – 1 stem
• 5 Gallon- 2-3 stems
• 10 Gallon – 4-5 branches or up to half of the tank if you like smaller canopies (I prefer less of my tank taken up by plants)
• 20 Gallon – 5-7 stems or up to 2/3rds of the tank if you like smaller canopies
• 29 Gallon- 8-10 stems or up to half of the tank if you like smaller canopies (I prefer less of my tank taken up by plants)
• 55 Gallon- 14-16 stems or up to 2/3rds of the tank if you like smaller canopies (I prefer less of my tank taken up by plants)
• 90 Gallon – 25+ contains or up to half of the tank if you like smaller canopies (I prefer less of my tank taken up by plants)
• This is a more difficult task than it sounds due to how fragile the plant can be. When I first started growing this plant,

I would usually have several leaves break off at the stem when moving them around, so consider this if you plan on planting them in different areas of your tank (like I do).

Water lettuce can also be grown through the use of cuttings. If you have a leaf over several inches, you can detach it from the main plant by cutting it at the base of where it meets the stem.

If you are new to this type of propagation, take your time and always cut at a shallow angle when removing parts of your water lettuce. I also recommend taking the mother plant out when doing this to reduce stress for both plants.

After you have clipped the piece you want, you can stick it in the substrate and wait for roots to grow or stick it in some rooting medium like aquatic plant soil.

I’ve done this numerous times and received a bad result only once. In that case, the clipping rotted shortly after I planted it on my substrate.

However, it could have been me rushing the process and not allowing enough time for roots to grow before planting them. Before cutting away from your mother plant, consider how long it takes to grow roots and whether you can adequately care for both plants.

Propagating this plant in another tank is pretty simple as well. If you remove part of the main plant, trim off any brown leaves or parts that look like they are rotting. Once the cutting has been cleaned, plant it on your substrate and wait for the roots to grow.

Dwarf Water Lettuce: Trimming And Pruning

Another way to control water lettuce is by pruning. This can be done by trimming off the top of your plant or at the leaf nodes where it branches out (typically 3-5).

The latter method will encourage new growth and make your plant smaller, but you don’t know how to remove larger chunks from the main plant.

In my experience, trimming off the top of your plant can be a bit more difficult due to how brittle the stems are.

I recommend using sharp scissors or clippers and holding onto the stem (don’t try to take it all in one cut). Trimming at the leaf nodes works well because you can gently bend the stem and snap it off.

This is helpful when your plant grows out of control or takes up too much of your tank.

If you prune either method, be sure not to remove more than ~20% of your total plant in one week. Otherwise, you may lose the plant altogether.

Caring For Water Lettuce

The details for proper care of Water Lettuce are given below.

Lighting

Dwarf water lettuce will grow best in a tank with bright lighting, although it can survive in lower light conditions.

If your tank’s lighting settings are turned to their highest, then this plant should receive enough light to grow quickly and densely. If not, be prepared to see slow growth and a lot of spacing between leaves.

If your aquarium receives too much light, it can cause golden algae to form in it, so you will need to fix this problem before putting any plants into the tank.

If you have a light leak somewhere in your aquarium is room, this could cause golden algae to form. If you have a light leak in your room, you must fix it before putting any plants into the tank.

Temperature

This plant will grow best in cooler water; the ideal temperature range is 72 to 86 degrees. If you decide to keep your tank warmer than this, then be prepared for more sparse growth and possible brown spots on the leaves.

If your water temperature is too low (about 60 degrees Fahrenheit or below), then this can cause golden algae to form in your tank, so you must fix this problem before putting any plants into the tank.

If your aquarium is receiving less than 70 degrees Fahrenheit of water temperature, then golden algae can form in it, so you will need to fix this problem before putting any plants into

pH Level

Water lettuce can survive at a pH level of 6.0 to 7.5 but will grow best at a pH level between 6.2 and 7.5. If your aquarium has a high pH level (above 8.2), then this can cause golden algae, so you must fix this problem before putting any plants into the tank.

This is especially true for Discus tanks, so be extra careful when it comes to the pH of your aquarium. If your aquarium has a low pH level (below 6.8) then this can cause golden algae, so you must fix this problem before putting any plants into the tank.

Water Movement And Quality

Dwarf water lettuce can survive in any water conditions suitable for most fish, but it cannot live or grow if the water is stagnant or murky. Because this plant grows so densely and covers so much surface area, it may require you to do more frequent water changes to keep the quality of your water up.

Nitrates And Other Nutrients

The optimum levels for nitrates and other nutrients are 10 ppm or below. If this number is higher than that, then you will need to perform more frequent water changes since too many nutrients can lead to excess algae growth.

Heater

Water lettuce does not require a heater to survive. Dwarf water lettuce will grow fine in a tank without a heater, but this plant may grow better if the temperature is kept at 70 degrees.

Filter

Water lettuce does not require a filter. Dwarf water lettuce will grow fine in a tank without a filter, but this plant may grow better if the tank is filtered. Dwarf water lettuce can do well in tanks with or without filters, but it may grow more quickly if the tank has a filter that moves at least 6 times the volume of your tank per hour.

Gravel

Dwarf water lettuce does best in tanks with sand or small gravel. Dwarf water lettuce will grow fine in a tank without substrate, but this plant may grow better if the tank has sand.

Tank Mates

Dwarf water lettuce is compatible with most fish and snails that are not too large. However, if the fish you add to your tank is aggressive, they may eat it. Dwarf water lettuce is compatible with most fish, but larger fish may uproot or eat this plant.

If your tank is overcrowded, then this can cause golden algae to form. To fix this problem, you must do some tank maintenance, clean out your filter and substrate, and then redistribute the fish into a larger aquarium.

Tank Size

Water lettuce can be kept in tanks that are 10 gallons or larger. Dwarf water lettuce can live in small tanks, but this plant grows more quickly and densely if put into a larger tank with plenty of room.

Size Of Plant

Dwarf water lettuce will grow best when the leaves on the plant do not touch each other. Dwarf water lettuce will grow in tanks where the leaves are crowded together, but this plant grows more slowly when the leaves are close to each other. Dwarf water lettuce will grow best in tanks with few or no other plants growing near it, so you must keep it separated from the other plants in your tank.

Placement

Dwarf water lettuce should be placed in the tank near the surface, which will receive bright lighting. Dwarf water lettuce can grow anywhere in your tank, but it will grow best if you place it towards the top of the tank, where the plant receives bright lighting.

Repotting

Dwarf water lettuce should be repotted when it grows outside of its pot or takes over the entire tank. Dwarf water lettuce can be placed anywhere in your tank, but make sure that you replace 1/3 of the soil every 2 years and check that the plant is not rotting from too much moisture.

Salinity

If your aquarium has a high salinity level (about 1.022-1.026), it can cause golden algae to form in it, so you must fix this problem before putting any plants into the tank.

Fertilizer

Overfeeding your fish or using too much fertilizer in your tank can also cause golden algae to form, so you must fix this problem before putting any plants into the tank.

Excess Amounts of Nutrients

If your aquarium has excess nutrients, this can lead to golden algae, so you will need to fix this problem before putting any plants into the tank.

Phosphate Problems

If your phosphate levels are high in your tank (over 0.03 ppm), then this can cause golden algae to form. You must fix this problem before putting any plants into the tank.

Excess Amounts of Ammonia

If your ammonia levels are high in your tank (over 0.5 ppm), this can cause golden algae to form, so you must fix this problem before putting any plants into the tank.

Acclimation Problems

If your plants were not acclimated properly before being added to your tank, then this can cause golden algae to form, so you will need to fix this problem before putting any plants into the tank.

Decorations

If you have decorations in your aquarium containing phosphorus, this can cause golden algae to start growing. Remove any decorations from the tank that contain phosphates and fix this problem before putting any plants into the tank.

Biotope

If your tank is not set up to resemble the natural environment of these plants, then this could cause golden algae to form.

To fix this problem, you will need to take some time and research what kind of environment these plants come from and make sure that your aquarium has those conditions as well.

Aeration Problems

If the aeration in your aquarium is not good enough, then this can cause golden algae to form in the water and on the glass of your aquarium.

To fix this problem, you must devise a way to ensure that the aeration in your aquarium is good.

Potential Diseases

If your plants suffer from any diseases, this can cause golden algae to start growing on them. To fix this problem,

you will need to take some time and research each of your plants individually to ensure they are not suffering from any diseases.

Potential Parasites

If your plants are infested with parasites, this can cause golden algae to grow on them. If you see your plants infested with parasites,

you must remove those plants from the tank and treat them before adding them back into the tank. You can use one of these treatments:

Potential Insects

If any insects are living on your plants, this can lead to golden algae forming on the plants, so you will need to get rid of any insects living on your plants.

Treatment For Diseases

If your plants are suffering from any diseases, then you will need to treat them for those diseases before adding them to the tank. To do this, you must research each plant individually and determine available treatment options.

Treatment For Parasites

If your plants are infested with parasites, you must remove them from the tank and treat them for the parasites before adding them back into the tank. You can use one of these treatments:

Copper

You can use copper to treat your plants for parasites. You will need to get a 4-6ppm solution of copper and then slowly drop it into the tank over several hours.

This method is often safer than other methods because it won’t kill any fish, but you will need to monitor the levels of copper in your tank to ensure that they don’t get too high.

Praziquantel

You can use praziquantel to treat your plants for parasites. You will need to get a 4-6ppm solution of praziquantel and then slowly drop it into the tank over several hours.

This method is often safer than other methods because it won’t kill any fish, but you will need to monitor the levels of praziquantel in your tank to ensure they don’t get too high.

Acriflavin + Salt

You can use a combination of acriflavine and salt to treat your plants for parasites. You will need to get a 4-6ppm solution of acriflavine and then slowly drop it into the tank over several hours. Once you do this, you must add salt to your tank.

Potassium Permanganate

You can use potassium permanganate to treat your plants for parasites. You will need to get a 4-5ppm solution of potassium permanganate and then slowly drop it into the tank over several hours.

This method is often safer than other methods because it won’t kill any fish, but you will need to monitor the levels of potassium permanganate in your tank to ensure they don’t get too high.

Treatment For Insects

If insects live on your plants, you must remove them before adding them to the tank. The easiest way to do this is to use a pair of tweezers and slowly pull all the insects off the plant. Then, once you have removed all of the insects from your plants, you can add them back into the tank.

Water Lettuce Care Guide For The Novice Aquarist

Step 1– Thoroughly inspect all plants before you buy them at a store.

Step 2- Make sure the plants have no brown pieces, and the leaves are still green. Sometimes, even if they look healthy in the store, aquatic plants can sustain damage to their leaves during transport. If you see any brown spots or all of the plant’s leaves are yellow, it will probably die in your tank, and you should not buy it.

Step 3- Rinse all plants thoroughly before putting them in your tank to get rid of any dirt or debris on them.

Step 4- Slowly put the plants in the tank to ensure they acclimate properly to their new environment.

Step 5- After putting all the plants in your tank, leave them to settle for about two hours before you turn your filter back on. This will give the plants enough time to ensure they are not leaking any nutrients into your tank (which can sometimes happen when new plants are put in the tank).

Step 6- Turn the filter back on once your plants are settled in for about 6 hours. The next day you can set it to run continuously if you like.

Step 7- If any of your plants start turning brown, you will need to remove them from the tank immediately. This means they are dead or dying, releasing nutrients into your tank.

Step 8- If you see any excess algae growing on the leaves of your plants, then you will need to remove them from the tank since they release too many nutrients into it. You can use a turkey baster with warm water in it, or tap water that has been put in a microwave for about 1 minute to suck up the algae. Then, safely dispose of the plants (by putting them in the garbage or outside since they are dead).

Step 9- If you see excess nutrients in your tank, siphon some of the water with a turkey baster into a jar with about two tablespoons of hydrogen peroxide. Squeeze out some toothpaste into the jar until it has a milky color to it, then put about one tablespoon of that into your tank. This will help clean out any excess nutrients.

Step 10- If you want to increase the speed at which your plants grow, you can feed them some liquid fertilizer or fish food after settling in for about 4-5 days.

Step 11- After about a month, all of your plants should have grown to their mature size. You can leave them in the tank if you like, but removing any excess nutrients from the water before transferring them back to your tank is best. This is done so you do not clog up your filter with extra nutrients.

Step 12- If any of your plants start to get brown around their leaves or stems, you will need to remove them from the tank immediately because they are dying and releasing too many nutrients into your tank.

Step 13- Remove any dead plants from the tank immediately so they do not rot and release excessive amounts of nutrients into your tank.

Step 14- If you have a golden algae problem in your tank, you must clean out all excess nutrients. To do this, siphon some of the water with a turkey baster into a jar with about two tablespoons of hydrogen peroxide. Squeeze some toothpaste into the pot until it has a milky color, then put about one tablespoon into your tank. This will help clean out excess nutrients and hopefully eliminate your golden algae problem.

Benefits Of Having It In Your Tank

• Shade For Fish: It provides shade for fish. Dwarf water lettuce has large, broad leaves that can give your fish a place to hide from the light so they don’t get overexposed. Plus, its roots growing in the substrate provide them with something to retreat into if they feel threatened.
• Food For Fish: The plant also provides a place for microorganisms to grow. Fish eats these tiny organisms and help supply their nutritional needs.
• Decoration: Water lettuce can be used as decoration because its long leaves stretch out across your aquarium water. Dwarf water lettuce works well because it doesn’t get too tall (under 10 inches) and provides good shade.
• Nitrate Reduction: Water lettuce helps reduce nitrates in your tank through photosynthesis. It is not as effective as plants like java moss or Anubis but still does a fairly decent job at absorbing excess nutrients from your tank.
• Easy To Maintain: Personal experience paired with the experiences of others have shown that water lettuce is a very easy plant to care for. This makes it a good choice for beginners and experienced fishkeepers alike.
• Use As A Bait Trap: Although this plant has never been used as a bait trap for me, I have seen reports of people using it to trap mosquito larvae. If you’re having problems with disease-carrying mosquitos in your tank, consider adding some water lettuce and see if that takes care of the problem.
• Safe For Other Plants: Unlike most plants, water lettuce does not produce any harmful chemicals to other live plants. This is beneficial if your tank contains a lot of fast-growing plants or stem plants because you won’t need to worry about some getting burned.
• A Cleaner Tank: With its large surface area, the plant helps create more oxygen and removes some water via transpiration. This can help keep your tank cleaner and reduce the need to do large water changes.
• May Help Reduce Algae Growth: Although water lettuce doesn’t exactly “fight” algae, the plant reduces its light exposure. By providing shade, you can help minimize how much light certain types of algae receive and further reduce their growth.
• Helps Keep Your Tank Cooler: The lower levels of your tank are usually cooler than the upper areas. This can help keep some of your fish cooler in warmer months and encourage them to breed (if that is what you’re hoping for).
• Keep Dust Down: Water lettuce helps prevent dust from escaping into the air by keeping it trapped at the top of your aquarium. By trapping this dust, you don’t have to worry about inhaling it or clouding your tank.
• Gives Your Fish A Place To Nap: When they aren’t swimming around and exploring their tank, most fish like to find a place to hang out and relax. Water lettuce provides them with a good hiding spot for this purpose since its leaves grow close to the surface.
• You Can Use It In A Pond: If you have a fish pond, you might want to add some water lettuce. This plant will grow in shallow areas and help keep your pond clean. Plus, the leaves have a nice wavy look that is aesthetically pleasing.

Cons Of Having It In Your Tank

A few cons are also associated with having dwarf water lettuce in your tank. The biggest one I’ve noticed is that it can be pretty invasive if you allow it to grow out of control. If this happens, your plant will take over parts of your tank and block out light from other plants behind it.

• Invasive-The leaves are long, thin, and fragile, making them perfect for growing into the substrate. Once they are in there, they can be tough to remove and will regrow from where you cut them.
• Slower Growth- Dwarf water lettuce grows quite quickly if given a lot of light and nutrients, but it takes its sweet time in lower light conditions. Some people had had to wait several months before their dwarf water lettuce produced its first set of leaves. This delay can be problematic for some people who want immediate results.
• Appearance– Although it is a pretty plant, in my opinion, I know there are many people out there who don’t like certain types of plants in their tank, no matter how attractive they are. If you fall into this category, I’d recommend not getting this plant or taking it out of your tank if you already have it.
• May Get Caught Up In Other Plants- Although this doesn’t happen to me very often, dwarf water lettuce can get caught up in other plants as they grow and consume more and more of the tank. Freeing the plant without damaging one or both of them can be difficult when this happens.
• Easily Distracted- Dwarf water lettuce is not a plant you want if you are trying to keep your tank visually interesting. Since its leaves grow in such big groups that they cover most of the plant’s surface area, finding a plant that can provide more color and interest may be tough.
• Can Cause A Lot Of Tinting In Your Water- Since the water lettuce is so big, you have to do more frequent water changes to keep it from tinting your tank’s water green.
• May Be Too Invasive For Some People’s Taste- Although many people love the way dwarf water lettuce looks, some don’t like it as much because of how invasive it can be. If you tend to have plants that are difficult to control, then I would not recommend getting this one.
• Doesn’t Transplant Well– Since dwarf water lettuce is so invasive, it doesn’t transplant all that well. When you detach parts of it from the main plant, they will take root wherever they land and grow into new plants. By the time you get the new dwarf water lettuce plant situated, a lot of leaves will probably have fallen off and taken root.
• Can Spread To Other Plants Easily– Dwarf water lettuce doesn’t usually attach to plants with its roots, but it can still spread to them through their leaves touching each other in the water. This is not a huge problem, but something to keep in mind if you have a lot of plants in your tank.
• Leaves Can Be Rough On Your Skin– Because these leaves grow very close to the surface of your aquarium, they can scrape against your skin while you are moving around inside it. Although this doesn’t happen often, it still isn’t pleasant and can irritate.
• Not Much Light Reaches The Bottom– Because the leaves grow so densely, a lot of light does not reach the bottom of your tank and, therefore, cannot be used by plants growing in this area. This is not usually a problem if you only have one or two dwarf water lettuce plants in your tank, but if you decide to get a lot of them, it could create an insufficient amount of light for other bottom-dwelling plants.
• Not The Most Colorful Plant– Because the leaves that grow from this plant are green, sometimes yellow, or red, depending on what kind you get and how much light they receive, there is little room for color in your tank.

Conclusion

Water lettuce will not survive long under its surface because its leaves cannot stay submerged long. This plant does not require substrate and can grow in water up to six feet deep.

Dwarf water lettuce is an excellent choice for beginning aquarists because it grows well in most conditions and doesn’t require much maintenance.

Although the plant looks very pretty, its leaves can become rough on your skin while walking around your aquarium, so always be careful when entering the water. I hope this article has helped you take care of your Dwarf Water Lettuce and stop any excess algae from growing in your tank.