Staring at a bare glass tank with a few plastic decorations gets boring fast. Worse yet, bare tanks often turn into green algae swamps within a few weeks.
Adding fast growing plants for aquarium setups solves both problems at the same time. Rapidly growing live plants act like natural sponges in your water. As they build new leaves and stems, they soak up fish waste, toxic ammonia, and nitrates. Because these plants eat up the nutrients in the water so quickly, ugly green algae starves out. Fast growers also give shy fish and newborn fry safe places to hide, which lowers stress across your whole tank.
You do not need expensive $CO_2$ gas tanks or blinding studio lights to grow a jungle underwater. Relying on established aquatic botany and general hobbyist knowledge rather than a single study, we have grouped the 12 best fast-growing aquarium plants by how they feed and where they go in your tank—so you can pick the exact right match for your setup.
Quick Comparison: Best Fast Growing Aquarium Plants at a Glance
|
Plant Name |
Tank Placement |
How It Feeds |
Light Needed |
Growth Speed |
|
1. Amazon Frogbit |
Floating (Surface) |
Water Column |
Low to Medium |
Very Fast |
|
2. Red Root Floater |
Floating (Surface) |
Water Column |
Medium to High |
Fast |
|
3. Salvinia Minima |
Floating (Surface) |
Water Column |
Low to Medium |
Very Fast |
|
4. Duckweed |
Floating (Surface) |
Water Column |
Any Light |
Extreme |
|
5. Hornwort |
Floating or Background |
Water Column |
Low to Medium |
Very Fast |
|
6. Guppy Grass |
Floating or Midground |
Water Column |
Low to Medium |
Fast |
|
7. Brazilian Pennywort |
Floating or Stems |
Water Column |
Medium |
Fast |
|
8. Anacharis (Waterweed) |
Background Stems |
Water Column & Roots |
Low to High |
Very Fast |
|
9. Water Wisteria |
Midground / Background |
Water Column & Roots |
Medium |
Fast |
|
10. Water Sprite |
Floating or Background |
Water Column & Roots |
Low to Medium |
Fast |
|
11. Vallisneria (Jungle Val) |
Background Wall |
Root Feeder (Substrate) |
Medium |
Fast (Once Settled) |
|
12. Pearlweed |
Carpet / Midground |
Water Column & Roots |
Medium |
Fast |
Fast Growing Floating Plants (Best for Sucking Up Nitrates)
Floating plants are the fastest-growing plants you can put in a fish tank. Why? Because they sit right at the top of the water. That gives them two huge advantages: they sit inches away from your aquarium light, and their leaves can breathe unlimited carbon dioxide ($CO_2$) straight from the air in your room.
If you struggle with high nitrates or green water, start with floaters. Just keep in mind one golden rule for all floating plants: they hate getting their top leaves wet. Keep your filter splash gentle so they don’t rot.
1. Amazon Frogbit (Limnobium laevigatum)
Amazon Frogbit looks like tiny lily pads floating on top of your tank. Underneath the water, it grows long, feathery white roots that hang down several inches. Small fish, bettas, and baby shrimp love swimming through these hanging roots to hunt for microscopic food and hide from bigger fish.
- Care Tip: Frogbit sends out side runners that pop up new baby plants every few days. If the roots grow too long and touch the bottom of your tank, you can trim them with clean scissors without hurting the plant.
2. Red Root Floaters (Phyllanthus fluitans)
If you want color other than green, Red Root Floaters are hard to beat. Under medium-to-bright LED lights, their round green leaves blush bright pink or deep crimson, and their underwater roots turn blood-red.
- Care Tip: Red Root Floaters hate strong surface currents more than almost any other plant. If your hang-on-back filter pushes them underwater, corralling them inside a floating airline tubing ring will keep them safe and dry.
3. Salvinia Minima (Water Spangles)
Salvinia minima is a tiny floating fern covered in microscopic, water-repellent hairs. If a drop of water lands on a leaf, it beads up and rolls right off. Because its roots stay fairly short (usually under an inch or two), it is a great pick for smaller 5-gallon or 10-gallon tanks where long Frogbit roots might clutter the swimming space.
4. Duckweed (Lemna minor) — And Why You Should Think Twice
Duckweed is likely the fastest-growing plant in the entire aquarium hobby. Under good light and nutrient-rich water, I believe its population can double approximately every 2 to 4 days—though exact growth rates depend on your tank temperature and fertilizer levels. It pulls massive amounts of ammonia and nitrates out of the water, and goldfish love eating it as a healthy green snack.
- The Catch: Hobbyists jokingly call Duckweed “aquarium glitter.” The tiny leaves stick to your hands, nets, and filter tubes. Once you put Duckweed in a tank, removing every single leaf is nearly impossible. Only add it if you don’t mind scooping out a handful every week!
Fast Growing Stem & Free-Floating Plants (Great for Plain Gravel or Bare Tanks)
Many beginners use plain aquarium gravel or sand that contains zero plant nutrients. If you plant heavy root-feeding plants in plain gravel, they starve.
The plants in this group are water column feeders. They drink up nearly all their food directly through their leaves and stems from the water around them. You can plant them in plain gravel, wedge them against driftwood, or just toss them into the water to float freely.
5. Hornwort (Ceratophyllum demersum)
Hornwort looks like bright green pine needles or a fluffy foxtail underwater. Interestingly, Hornwort never grows true roots at all. If you push the bottom stem into the gravel, the buried part will often rot and float back up. Instead, let it float near the surface, or loop a gentle lead plant weight around the base to anchor it at the back of your tank.
- Care Tip: According to botanical profiles from the University of Florida Center for Aquatic and Invasive Plants, Hornwort thrives in a wide range of water temperatures and helps oxygenate water while shading out nuisance algae. However, do not use liquid “liquid carbon” algicides (like glutaraldehyde products) in a tank with Hornwort—it will cause the plant to drop all its needles overnight.
6. Guppy Grass (Najas guadalupensis)
True to its name, Guppy Grass is the ultimate plant for livebearers like guppies, platies, endlers, and mollies. It grows into a tangled, bushy green web where newborn baby fish can hide the second they are born, keeping them safe from hungry adult fish.
- Care Tip: Guppy Grass has brittle stems that snap easily if you move them around. Don’t worry if a piece breaks off—every broken piece will simply start growing into a brand-new bush!
7. Brazilian Pennywort (Hydrocotyle leucocephala)
With bright green, coin-shaped leaves that grow along a winding vine, Brazilian Pennywort adds a cheerful, tropical look to any tank. You can plant the stems in the substrate and watch them climb toward the light, or let the vine float across the top of the water like a canopy. Little white roots will sprout at every leaf node along the stem to drink up nitrates from the water.
8. Anacharis / Brazilian Waterweed (Egeria densa)
For decades, Anacharis has been the classic classroom biology plant because it is nearly indestructible. It grows fast in cold goldfish tanks and warm tropical tanks alike. Under moderate light, stems can grow several inches a week.
- Important US Legal Note: Because Egeria densa grows so aggressively in the wild, it is listed as a restricted or noxious weed in several US states (you should verify your current state agricultural rules before ordering, as regulations change over time). If it is restricted in your state, Hornwort or Water Sprite are safe, legal alternatives that look and work great.
Fast Growing Rooted Plants (For Background & Midground Coverage)
If you want a classic underwater garden with tall background walls and lush bushy corners, rooted plants are your best friend. While these plants still absorb nutrients from the water, they grow much faster when you push their roots into nutrient-rich aquasoil or place aquarium root tabs (fertilizer capsules) under the gravel near their base.
9. Water Wisteria (Hygrophila difformis)
Water Wisteria features lacy, bright green leaves that look like delicate snowflakes or fern fronds. It grows tall and wide very quickly, making it ideal for hiding ugly black heater cords and filter tubes in the back corner of your aquarium.
- Cool Plant Fact: The shape of Water Wisteria’s leaves actually changes based on your tank’s light and temperature. Under brighter light, the leaves develop deep, jagged cutouts; under lower light, the leaves grow wider and flatter to catch more rays.
10. Water Sprite (Ceratopteris thalictroides)
Often confused with Water Wisteria, Water Sprite is a true aquatic fern with even finer, softer, feathery leaves. It is one of the most versatile plants you can buy: you can plant its roots in the gravel as a background bush, or leave it floating at the surface for Gouramis and Bettas to build bubble nests in. Tiny baby plants will even sprout right on the edges of older leaves!
11. Vallisneria / Jungle Val (Vallisneria americana)
If you love the look of tall underwater grass swaying in the filter current, Vallisneria is for you. Native to North and Central America, its long ribbon-like leaves grow straight up to the water’s surface and then lay flat across the top.
- How It Grows: Jungle Val often sits still for the first 2 to 3 weeks while it builds roots under the gravel. Once it settles in, watch out! It shoots out underground side runners across the bottom of the tank, popping up new grass blades every few inches until you have a thick green curtain along the back glass.
12. Pearlweed (Hemianthus micranthemoides)
Most low-growing “carpet” plants (the ones that look like a green lawn across the bottom of the tank) grow very slowly and demand high-tech $CO_2$ injection. Pearlweed is the exception. It has tiny, bright green leaves on dainty stems that grow rapidly in normal, low-tech tanks.
- Care Tip: Left alone, Pearlweed grows upward into a tall, dense bush. If you trim the tops down regularly with scissors and push the cut tops into the gravel next to the main plant, you can train it to spread out like a thick green carpet.
Why Your “Fast Growing” Plants Are Dying (And How to Fix It)
Even the easiest plants on this list can struggle if you get caught off guard by a few common beginner traps. Here is how to troubleshoot struggling plants:
Understanding Initial “Plant Melt”
Here is a secret most pet stores forget to tell you: most aquarium plants sold in the US are grown out of water (emersed) in humid greenhouses at the plant farm. Growing them in open air is faster for nurseries and keeps the plants free of snails and algae.
When you bring a greenhouse-grown plant home and put it underwater, its air-grown leaves cannot breathe underwater. Over the first 1 to 2 weeks, the old leaves will turn yellow, brown, or mushy and fall off. Do not throw the plant away! As long as the main stem or roots feel firm, the plant is alive. Just snip off the rotting old leaves so they don’t dirty your water, and watch fresh, underwater-adapted leaves sprout from the center within days.
Preventing Nutrient Starvation (Liquid Fertilizer vs. Root Tabs)
Fast growth takes fuel. If a plant doubles in size in two weeks, it quickly eats up all the natural trace minerals (like potassium, iron, and nitrogen) in your tap water. Once the food runs out, fast-growing plants start developing tiny pinholes in their leaves, or their bottom leaves turn pale yellow.
- For Floating and Stem Plants: Add a few pumps of an all-in-one liquid aquarium fertilizer once a week after your water change.
- For Rooted Plants (like Vallisneria and Wisteria): Push clay or capsule root tabs deep under the gravel or sand near the plant roots every 2 to 3 months.
Lighting Schedules and Surface Flow
More light is not always better. Leaving your aquarium light on for 14 hours a day will not make your plants grow twice as fast—it will just cover their leaves in black beard algae or green hair algae. Put your aquarium light on a simple wall timer for 6 to 8 hours a day. Plants need a dark nighttime rest period just like fish do.
How to dispose of extra trimmings safely:
- Scoop out the unwanted plants or Duckweed.
- Lay them out on paper towels in the sun until they are completely bone-dry (or freeze them solid in a sealed bag overnight).
- Seal the dead plants inside a plastic trash bag and place them in your regular household garbage—or mix them into a land-based garden compost bin away from natural water sources.
Frequently Asked Questions (FAQs)
- What is the absolute fastest growing aquarium plant?
Duckweed (Lemna minor) and Hornwort (Ceratophyllum demersum) are the two fastest-growing plants for home aquariums. Duckweed floats on the surface and can double its coverage in just a few days, while Hornwort grows rapidly underwater without needing roots or substrate.
- Do fast growing aquarium plants need $CO_2$ injection?
No. All 12 plants on this list thrive in standard, low-tech aquariums without pressurized $CO_2$ equipment. Floating plants like Amazon Frogbit and Salvinia pull unlimited carbon dioxide straight from the room air, while hardy underwater plants like Hornwort, Water Sprite, and Vallisneria easily use the small amounts of natural $CO_2$ produced by your fish and filter bacteria.
- Can fast growing plants grow in plain gravel or sand?
Yes! Water column feeders—including Hornwort, Guppy Grass, Anacharis, Java Moss, and all floating plants—take in their nutrients straight from the water through their leaves. They do not need special plant soil and will grow rapidly in plain gravel, sand, or even a bare-bottom tank as long as there is fish waste or a few drops of liquid fertilizer in the water.
- How often do you need to trim fast growing stem plants?
In a healthy tank with medium light, fast-growing stem plants like Water Wisteria, Brazilian Pennywort, and Pearlweed usually need a quick trim every 2 to 3 weeks. Simply snip the top half of the stem with clean scissors. You can throw the trimming in your garden compost, or push the cut top right back into the gravel to grow a brand-new plant for free!
- Do live plants lower ammonia and nitrates in a fish tank?
Yes. Fast-growing live plants love eating nitrogen compounds—including fish waste ammonia, nitrite, and nitrate—to build new green leaves. While live plants do not replace your filter or weekly water changes, a tank heavily planted with fast growers will have much cleaner, safer water than an unplanted tank.
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