Pothos, also known as Epipremnum aureum or devil’s ivy, is a popular houseplant known for its trailing vines and ease of care. Its ability to grow in water makes some aquarium owners wonder if they can incorporate pothos into their fish tank decor. There are pros and cons to consider when putting pothos in an aquarium.
What is Pothos?
Pothos is a tropical vine native to the Solomon Islands. It is an evergreen perennial that can thrive as a houseplant or outdoors in USDA growing zones 10-11. Pothos has heart-shaped green leaves that can vary from 1-4 inches long. Under the right conditions, the leaves develop black, white, or yellow variegation.
There are a few different Pothos cultivars:
- Golden pothos – This variety has golden yellow leaves. It is the most popular type of pothos.
- Marble Queen – Leaves are green with white variegation.
- Neon pothos – Leaves are bright neon green.
- Pearls and Jade – Leaves are dark green with white speckles.
- Manjula – Leaves are pale green and white.
Pothos is called devil’s ivy because it is almost impossible to kill and stays green even when neglected. It can thrive in a wide range of conditions which makes it a favorite for beginner plant owners.
Can You Put Pothos in a Fish Tank?
Yes, you can put pothos in a fish tank. Pothos can grow fully submerged in water or partially submerged with its roots underwater and leaves and stems above water.
Adding pothos to an aquarium can provide the following benefits:
- Aesthetic appeal – The trailing vines and green leaves can be an attractive addition to aquarium decor.
- Oxygenation – The pothos will release oxygen into the water through photosynthesis. This helps create a healthy environment for fish.
- Nitrate removal – The plant will absorb nitrates in the water, helping keep levels low. Excess nitrates can be harmful to fish.
- Additional surface for beneficial bacteria – The submerged parts of the plant, especially the roots, provide surface area for helpful nitrifying bacteria to grow. These bacteria aid the nitrogen cycle.
- Shelter – Fish may hide or rest in the leaves and roots of the pothos, especially shy species like bettas.
- Fry protection – In a fish breeding tank, the dense leaves shelter and protect fish fry from adult fish that might eat them.
So adding pothos can potentially help create a healthier, more natural environment in your aquarium. But there are also some potential downsides to consider.
Disadvantages of Adding Pothos to a Fish Tank
While pothos can benefit an aquarium, there are also some risks:
Space Constraints
Pothos vines can grow up to 10 feet long in ideal conditions. But most home aquariums are much smaller than that. The fast, vigorous growth of pothos can quickly overrun a small tank.
You’ll need to frequently trim the vines back to keep the plant contained. Even then, it takes up a lot of horizontal space at the top of the tank as it spreads out. Make sure you have room to accommodate the plant’s growth. Slow growing varieties like Manjula or Pearls and Jade are better options for smaller tanks.
Reduced Light for Other Plants
If the pothos vines cover the entire water surface, this will significantly reduce the light entering the aquarium. Plants like aquatic mosses, stem plants, and carpet plants need lots of light to thrive. Blocking light with a canopy of pothos leaves means these plants won’t grow well.
Only use pothos in tanks with other low-light plants or tanks without other plants. Leaving some open areas in the leaves can allow some light through.
Potential to Rot
While pothos can grow fully submerged, it’s better suited to have its leaves and stems above water. If the leaves remain underwater for too long they are prone to rotting. Make sure at least some of the vines can grow out of the top of the tank.
Trim away any leaves that are fully submerged before they start deteriorating. You can also grow pothos in a pot with the roots underwater but leaves and stems above the water line.
Could Shelter Pests
The dense leaves and root systems can provide hiding places for unwanted tank pests. Snails like nerites and ramshorn thrive in planted tanks and their eggs could get lodged in the pothos roots. Aquarium shrimp like cherries could also multiply rapidly amidst the protection of the vines.
Do regular checks beneath the leaves to monitor for unwanted populations explosions. Remove sections of vines or trim leaves to dislodge hitchhikers when needed.
May Absorb Medications
Activated carbon is sometimes used in aquariums to filter out medications after fish treatments. Pothos may have a similar effect, absorbing dissolved medications before they fully treat the fish.
It’s best to remove pothos before dosing tank medications. Then wait a day or two before returning the plant to ensure it doesn’t reduce medication effectiveness.
How to Plant Pothos in a Fish Tank
If you want to add pothos to your aquarium, follow these steps for success:
Choose the Right Tank
Opt for a larger tank if possible, at least 10 gallons or more. This gives the pothos room to grow without taking over. Nano tanks under 5 gallons are generally too small to accommodate the plant.
Also avoid crowded community tanks with lots of fish. The plant thrives best in peaceful setups like betta tanks or lightly stocked community tanks. Tanks with fast-moving species that could uproot the plant are not ideal.
Make sure the tank has adequate filtration and regular water changes. While pothos helps with nitrates, it’s not a substitute for proper tank maintenance.
Pick the Best Location
Place the pothos at the back of the tank where it can grow along the rear wall and spread out across the surface. Keep lower and slower growing plants near the front.
You can use aquarium-safe silicone or suction cups to attach the vines to decorations like driftwood. But leaving the roots bare to dig into the substrate is best.
Position broad leaf varieties like Golden Pothos to maximize surface coverage while allowing some light through. Use slower growing types like Manjula in the corner to minimize size.
Avoid planting directly under the outlet of hang on back filters where the current could batter the vines.
Use the Right Substrate
Plant the pothos in aquarium gravel or a nutrient-rich substrate. Sand alone is too compact for the roots to take hold. Combining sand with a thin gravel cap provides the best foundation.
Spread root tabs around the base periodically to provide key nutrients, especially iron. Liquid fertilizers can also dose the water column but are rapidly diluted.
Propagate in Water
Start with a rooted pothos clipping if possible. Take a 6 inch vine cutting with a few leaves. Trim off the lowest set of leaves and place it directly in the substrate. New roots will emerge in a few weeks.
Or place the cutting in a glass of water first. Once root hairs develop submerge the cutting in the tank. This encourages the fastest transition to underwater growth.
Avoid transplanting a houseplant directly into the aquarium. The dry starts method helps the roots acclimate.
Let Leaves Reach the Surface
As the pothos grows, let some vines extend out of the top of the tank while other leaves remain submerged. Floating leaves have access to air which is less prone to rot and allows photosynthesis.
Trim any fully inundated leaves showing decay before they compromise the rest of the plant. But let healthy underwater leaves remain for nitrate absorption.
A emergence rate of about 20% is ideal. Slowly increase the number of exposed leaves as the plant adapts to aquatic life.
Control Growth
Use aquarium-safe scissors to regularly trim pothos vines. Cutting just above a leaf node encourages branching vines. Discard any rotting or deteriorating leaves promptly.
To limit horizontal expansion, periodically thin dense clumps of vines back to just 2 or 3 per square inch. Focus on removing the fastest growing sections first.
Remove vines that root in the substrate and creep along the bottom. They often lose leaves and look scraggly without light. Careful pruning keeps growth controlled.
Getting Pothos to Flower in an Aquarium
Getting pothos to produce its white flowering spathes in an aquarium is challenging but possible with pristine water conditions. Here’s a quick guide:
- Ensure the tank size is at least 20 gallons to accommodate the plant’s maximum size.
- Only keep a few small, peaceful fish that won’t disturb the roots like a betta, guppies, or neon tetras.
- Use soft water with a pH below 7 and low KH levels. Pothos prefers acidity.
- Maintain ammonia, nitrites, and nitrates at 0 ppm with frequent partial water changes and high filtration.
- Provide bright aquarium lighting on for 12-14 hours daily. High PAR levels encourage flowering.
- Let the pothos reach its full size with vines trailing well above the tank. Mature, healthy plants are more likely to bloom.
- Be patient. It can take over a year of ideal aquatic conditions before spathes may emerge. But the wait is worth it for these rare aquarium flowers!
Even doing everything right, pothos may fail to flower submerged. But you can enjoy the lush leaves and helpful properties in the meantime.
Best Fish for Pothos Tanks
Many popular aquarium fish do well when combined with pothos:
- Bettas – Betta splendens thrive with dense leaves to explore and rest on. The plant offers shelter, reduces reflections they flare at, and helps filter their sensitive labyrinth organ.
- Guppies – Fancy strains with flashy fins appreciate resting spots andfry protection. The vines provide safety and dispersed light for their eyes.
- Tetras – Small tetras like embers and neons enjoy planted tanks. Pothos gives them places to take cover and helps keep water clean.
- Gouramis – Slow moving gouramis like honey and pearl especially like nooks in leaves for retreats. Their long fins are also less prone to damage.
- Plecos – Algae eating plecos help clean plant leaves. Resting plecos will attach to broad leaves with their sucker mouths.
- Mollies – These livebearers utilize the plant to hide while giving birth and sheltering fry. Just watch for nipping at leaves.
- Corydoras – Armored catfish cats crawl on leaves searching for bits of food. Their protective barbels are safe from damage.
- Killifish – Many top dwelling killies appreciate floating leaves for insect-like habitats and obstructing light.
Avoid pairing pothos with known plant nibblers like goldfish, cichlids, or silver dollars that may eat it.
Aquarium Pothos Tips
Follow these top aquarium pothos tips:
Start with Young Cuttings
Younger, smaller vines adapt to underwater life better than large houseplants with established roots. Use 6 inch cuttings from healthy stems.
Quarantine First
Before introduction, observe pothos cuttings in a separate tank for a few weeks to check for pests like snails. This prevents introducing issues to your display.
Anchor With Weights
To submerge initially, attach a small rock or other weight to the cutting to keep it under until roots form. Then remove the weight.
Wipe Away Algae
Clean off any unsightly green algae growing on the emerged leaves with a soft cloth to keep your tank looking neat.
Alternate Varieties
Mix different pothos cultivars like Pearls and Jade and Manjula to add visual diversity with contrasting leaves.
Use Root Tabs
Place sinking fertilizer tabs around the base of the vines every 3-4 months to supplement nutrients. Monitor using test kits.
Never Overcrowd
While a few pothos plants enrich tanks, overplanting leads to excessive pruning and rotting. Start with conservative amounts and slowly increase.
Common Pothos Problems and Solutions
| Issue | Cause | Solution |
|---|---|---|
| Leaves Turning Yellow | Nitrogen deficiency | Add liquid fertilizer or root tabs |
| Rotting Lower Leaves | Insufficient light | Raise light or trim submerged leaves |
| Tips Turning Brown | Fluctuating CO2 levels | Improve water movement at surface |
| Stunted Growth | Low nutrients | Dose iron supplement |
| Algae on Leaves | Excess lighting duration | Reduce photoperiod to 8 hours |
Conclusion
Pothos is a great way to incorporate helpful live plants into your aquarium with minimal maintenance required. Taking the time to properly plant and care for pothos can reward you with a beautiful accent. Just be aware of the potential for aggressive and leggy growth in smaller tanks. With a little effort controlling its expansion, both your fish and pothos can thrive together in harmony.
Frequently Asked Questions
Can pothos grow underwater?
Yes, pothos can grow fully submerged but it grows better with the stems and leaves emerging above the water. Keeping some leaves floating allows for photosynthesis and gas exchange. The underwater roots readily absorb nutrients.
Is pothos good for aquariums?
In most cases pothos is beneficial for tanks. Its ability to uptake nitrates helps with water quality. And it provides shelter, breeding sites, and enhanced oxygenation. Just be cautious of aggressive, unchecked growth.
Why are my pothos leaves turning brown underwater?
If the leaves turn brown and mushy when submerged it is likely due to rotting from insufficient light. Allow some leaves to reach the surface and trim deteriorating leaves immediately to stop spread.
Can pothos be attached to driftwood?
Yes, pothos can attach directly to driftwood above or below the water line using silicone or fishing line. The roots will dig into the wood over time. Driftwood provides beneficial tannins too.
What fish eat pothos?
Pothos is not especially tasty to most aquarium fish. But larger cichlids, goldfish, and catfish may nibble at leaves. Make sure you have hardy, established vines before adding them to these tanks.
Does pothos reduce nitrites?
While not as efficient at removing nitrites as nitrates, pothos can help lower potentially harmful nitrite levels by absorbing some through its roots and leaves.
Can pothos grow in low light tanks?
Pothos tolerates lower light than many aquarium plants, even down to less than 2 watts per gallon. Growth will be slower but it allows it to work in darker tanks. Combine with Anubias, Java Fern, and moss.
How long do pothos live?
Given proper care, pothos typically lives for 5-10 years indoors. It can potentially reach up to 40 feet in its native tropical habitat. Maintaining optimal conditions can maximize its lifespan in an aquarium.
Can pothos grow emersed then submersed?
Starting pothos emersed or in a pot with just the roots underwater makes adapting to fully aquatic life easier. Allow time for the leaves to slowly adjust to being submerged to prevent shock.