Philodendron In Fish Tank – The Ultimate Guide To Natural Nitrate
Are you tired of battling high nitrate levels despite regular water changes?
Most aquarists agree that maintaining a biological balance in a closed glass box is the most challenging part of the hobby.
I promise you that adding a philodendron in fish tank setups is one of the most effective, low-cost “hacks” to achieve crystal-clear water and a thriving ecosystem.
In this guide, we will explore which species work best, how to safely transition them from soil to water, and the secrets to keeping both your plants and your fish healthy.
Why You Should Add a Philodendron in Fish Tank Setups
Adding terrestrial plants to an aquarium—a style often called a riparium—is more than just a decorative trend.
It is a powerful biological tool that mimics how natural riverbanks function in the wild.
The Ultimate Nitrate Sponge
While aquatic plants like Anubias or Java Fern are beautiful, they grow relatively slowly compared to terrestrial tropicals.
A philodendron in fish tank environments grows much faster because it has access to atmospheric carbon dioxide (CO2).
Because it grows faster, it consumes massive amounts of nitrogenous waste, specifically nitrates, which are the end product of the nitrogen cycle.
By pulling these nutrients out of the water, the plant helps prevent algae blooms and reduces the frequency of necessary water changes.
Natural Shelter and Fry Protection
The root systems of a philodendron are incredibly dense and intricate once they established.
These “root jungles” provide the perfect hiding spots for shy fish, such as Sparkling Gouramis or small tetras.
If you are a shrimp keeper, you will find that your cherry shrimp love grazing on the biofilm that naturally forms on the submerged roots.
Furthermore, if you have breeding fish, the roots offer a safe haven for fry to hide from hungry adults.
Enhanced Aesthetics and Room Humidity
Beyond the water line, the large, waxy leaves of a philodendron add a lush, jungle-like feel to your room.
They also help slightly increase the humidity around the tank, which can be beneficial for other houseplants and even your own respiratory health during dry winters.
Top Philodendron Species for Your Aquarium
Not every philodendron is created equal when it comes to living with its “feet” wet.
You want species that are hardy, fast-growing, and adaptable to various lighting conditions.
Heartleaf Philodendron (Philodendron hederaceum)
This is the gold standard for beginners.
It features classic heart-shaped, deep green leaves and is incredibly resilient.
It can tolerate lower light levels, making it perfect for tanks that don’t have high-end specialized LED arrays.
Philodendron ‘Brasil’
If you want a splash of color, the ‘Brasil’ cultivar is a fantastic choice.
It features stunning lime-green and yellow variegation down the center of each leaf.
In my experience, the ‘Brasil’ grows just as fast as the standard heartleaf, provided it gets a bit more indirect sunlight to maintain its colors.
Philodendron Micans
For a more sophisticated look, the Philodendron micans offers velvety, iridescent leaves that shimmer under aquarium lights.
The undersides of the leaves are often a deep burgundy or bronze color.
While it is slightly more sensitive than the standard heartleaf, it creates a breathtaking “curtain” effect when allowed to trail down the sides of a rimless tank.
How to Safely Transition Your Philodendron to Water
You cannot simply toss a potted plant into your aquarium; doing so would introduce fertilizers, pesticides, and decaying soil into your delicate ecosystem.
Follow these steps to ensure a safe transition for your philodendron in fish tank project.
Step 1: Selecting the Cutting or Plant
You have two choices: use a fully grown plant or take a cutting from a healthy mother plant.
If using a cutting, ensure it has at least 2-3 nodes (the little bumps on the stem where roots and leaves emerge).
Cuttings often adapt faster to water because they grow “water roots” from the start, rather than converting “soil roots.”
Step 2: Thorough Root Cleaning
If you are using a plant that was previously in soil, you must be meticulous.
Remove the plant from its pot and gently shake off the loose dirt.
Submerge the roots in a bucket of lukewarm dechlorinated water and massage the root ball to remove every speck of soil.
PRO TIP: Use an old soft toothbrush to get into the crevices of the root system to ensure no organic matter remains, as this can rot and cause an ammonia spike.
Step 3: The Quarantine Phase (Optional but Recommended)
If you bought the plant from a big-box hardware store, it likely contains systemic pesticides or leaf shines that are toxic to fish and shrimp.
Place the cleaned plant in a jar of dechlorinated water for 5-7 days, changing the water daily.
This “leaches” out any residual chemicals before the plant enters your main display tank.
Practical Methods for Mounting Your Plant
Since philodendrons are not true aquatic plants, their leaves must remain above the water line while their roots stay submerged.
If the leaves are submerged for too long, they will eventually melt and rot.
Using Rim-Mounted Planters
The easiest way to secure a philodendron in fish tank setups is by using specialized 3D-printed clips or “pothos holders.”
These hang over the edge of the glass and hold the stems securely in place while allowing the roots to dangle freely into the water column.
The Suction Cup Method
For a more DIY approach, you can use airline tubing suction cups.
Simply thread the stem through the plastic loop of the suction cup and attach it to the inside of the glass just above the water line.
This is a great way to “train” the vines to grow along the back wall of your aquarium.
Using Egg Crate or Mesh Covers
If you have a lid on your tank, you can replace a small section with plastic “egg crate” (light diffuser).
You can then poke the stems through the holes in the grid.
This provides excellent support for larger, heavier plants and prevents them from falling into the water.
Lighting and Nutrient Requirements
While the fish waste provides the majority of the nutrients, you still need to pay attention to the plant’s basic needs.
Light Exposure
Philodendrons thrive in bright, indirect light.
They do not need the intense, full-spectrum lights required by high-tech carpeting plants.
Usually, the ambient light in a well-lit room or the “spillover” light from your aquarium LED is more than enough.
However, if you notice the leaves becoming small or the stems becoming “leggy” (long gaps between leaves), you may need to add a small grow light nearby.
Monitoring Nutrient Deficiencies
Even with plenty of fish waste, your philodendron might run out of specific micronutrients.
If you see yellowing leaves with green veins, it may be a sign of iron or magnesium deficiency.
In these cases, I recommend using a high-quality liquid fertilizer that is safe for aquarium inhabitants.
Be careful not to over-fertilize, as the combination of fish waste and added nutrients can lead to an explosion of green water (unicellular algae).
Addressing Safety Concerns: Is Philodendron Toxic to Fish?
A common question among hobbyists is whether the calcium oxalate crystals found in philodendrons are dangerous.
It is true that philodendrons are toxic if ingested in large quantities by mammals.
However, in an aquarium setting, they are generally considered safe.
Why It Is Safe for Most Fish
Most fish do not have the mouthparts or the desire to eat the tough, fibrous roots of a philodendron.
Even herbivorous fish like Silver Dollars or large Cichlids usually find the roots unappealing.
The primary danger occurs if a stem is snapped or crushed inside the water, releasing a large amount of sap at once.
In a well-maintained tank with good filtration, the occasional broken root is not a cause for concern.
Special Considerations for Shrimp and Snails
Shrimp are particularly sensitive to chemical changes.
If you are keeping high-grade Neocaridina or Caridina shrimp, be extra diligent during the cleaning and quarantine phase.
Once the plant has transitioned to its “water roots,” it is perfectly safe for shrimp to climb on and clean.
Maintenance and Long-Term Care
A philodendron in fish tank environment is relatively low-maintenance, but it does require some “housekeeping” to keep it looking its best.
Pruning the Roots
Over time, the root system can become massive, potentially blocking water flow or taking up too much swimming space.
Don’t be afraid to trim the roots with a pair of sharp, sterilized scissors.
Trimming about 20-30% of the root mass at a time is perfectly safe and actually encourages the plant to grow more “feeder roots” which are more efficient at pulling out nitrates.
Cleaning the Leaves
Dust can accumulate on the leaves of your riparium plants, blocking their ability to photosynthesize.
Every few weeks, gently wipe the leaves with a damp cloth using dechlorinated water.
This keeps the plant healthy and ensures it continues to act as an effective biological filter.
Managing the Growth Direction
Philodendrons are climbers and trailers by nature.
If you want them to grow up your wall, you can provide a moss pole or small command hooks to guide the vines.
If you prefer a bushy look, pinch off the growing tips periodically to encourage lateral branching.
Common Problems and Troubleshooting
Even the most experienced aquarist encounters issues occasionally.
Here is how to solve the most common “philodendron in fish tank” problems.
The Leaves are Turning Yellow and Falling Off
This usually happens right after the transition from soil to water.
The plant is likely shedding its “air leaves” to focus energy on growing “water roots.”
As long as you see new, green growth at the tips, don’t panic.
Simply remove the yellowing leaves so they don’t fall into the water and rot.
The Roots are Turning Brown and Mushy
This is a sign of root rot, often caused by poor water circulation or leftover soil.
If you see mushy roots, remove the plant immediately and trim away the dead sections.
Rinse the remaining healthy roots in a diluted hydrogen peroxide solution (3%) before placing the plant back in an area with better water flow.
Algae Growing on the Roots
If your roots are covered in hair algae or green fuzz, it usually means they are getting too much direct light.
Try to shade the root area using floating plants or by adjusting the angle of your aquarium light.
Adding a few Amano shrimp or Nerite snails can also help keep the roots sparkling clean.
FAQ: Philodendron in Fish Tank
Can I grow a philodendron fully submerged?
No. While the roots love being underwater, the leaves and stems will eventually rot if they remain submerged for more than a few days. Always ensure the foliage is in the open air.
Will a philodendron kill my fish?
No, as long as the plant is properly cleaned before being added. The sap is an irritant, but fish typically do not eat the roots.
Does it replace the need for a filter?
While a philodendron in fish tank setups provides excellent biological filtration, it does not provide mechanical filtration (removing floating particles). You should still use a traditional filter alongside your plants.
How fast will it grow?
In a nutrient-rich aquarium, you can expect several inches of new vine growth per month during the warm season.
Can I use a Pothos instead?
Yes! Pothos (Epipremnum aureum) is often confused with Philodendron and works in exactly the same way. Both are excellent choices for nitrate removal.
Final Thoughts
Integrating a philodendron in fish tank designs is one of the most rewarding ways to bridge the gap between indoor gardening and fish keeping.
It creates a more stable environment for your aquatic pets while providing you with a beautiful, low-maintenance houseplant.
By following the cleaning and mounting steps outlined above, you can turn your aquarium into a true slice of the tropical rainforest.
Don’t worry—this setup is perfect for beginners!
Start with a small cutting, watch those roots grow, and enjoy the benefits of a cleaner, healthier aquarium.
Happy fish keeping!
