Keeping your aquarium water clean is a constant task for any fish keeper. One of the most common issues is high nitrate levels, which can stress your fish and fuel algae growth. Using pothos to lower nitrates in aquarium setups is a brilliant, natural method that many hobbyists are now adopting. This easy-to-grow houseplant isn’t just for your living room; it’s a powerful, living filter for your tank.
This approach, often called aquaponics, lets the plant use the nutrients from fish waste as its food. It’s a win-win situation. Your pothos gets a steady supply of fertilizer, and your aquarium water gets purified. Let’s look at how you can set this up and why it works so effectively.
Pothos To Lower Nitrates In Aquarium
The science behind this method is straightforward. In an aquarium, fish produce ammonia. Beneficial bacteria convert this ammonia first into nitrite and then into nitrate. While less toxic, nitrates accumulate over time and are typically removed by water changes. Pothos plants offer another solution.
Pothos roots, when submerged in the aquarium water, absorb these nitrates directly. They use the nitrogen to grow new leaves and stems. This process directly removes the nitrate from the water column before it can reach problematic levels. It’s a natural form of filtration that complements your existing filter.
Why Pothos is the Perfect Choice
Many plants can grow in water, but pothos stands out for several key reasons. Its hardiness and adaptability make it ideal for beginners and experts alike.
* Extremely Hardy: Pothos is famously difficult to kill. It tolerates a wide range of water conditions, pH levels, and light situations.
* Fast Growth: A healthy pothos grows quickly, especially with a constant nutrient supply from your tank. Faster growth means more nitrates are consumed.
* Readily Available: You can find pothos (Devil’s Ivy) at almost any garden center or even get a cutting from a friend. It’s very inexpensive.
No Special Lighting Needed: Unlike many aquatic plants, pothos grows its leaves above the water. It uses standard room light, so you don’t need powerful aquarium lights for it to thrive.
What You’ll Need to Get Started
Setting up pothos in your aquarium is simple and requires minimal supplies. You probably have most of these items already.
* Pothos Cuttings: Get a few healthy stems with several leaves and visible nodes (the little bumps on the stem).
* A Method to Suspend the Plant: You’ll need a way to hold the plant so only its roots are in the water. You can use suction cup plant holders, clip-on baskets, or even a piece of driftwood or the tank’s filter box.
* Scissors or Pruners: For taking and trimming cuttings.
* Patience: It takes a week or two for the cuttings to develop water roots and start working efficiently.
Step-by-Step Setup Guide
Follow these simple steps to introduce pothos into your aquarium safely and effectively.
1. Take Your Cuttings. Using clean scissors, cut a stem section about 6 inches long. Make sure each cutting has at least 3-4 leaves and 2-3 nodes. The nodes are where the new roots will sprout from.
2. Prepare the Cuttings. Remove any leaves that would be submerged under water. Leaves rotting in the water can pollute it, so only the bare stem should be below the surface.
3. Choose Your Placement. Decide where you want the plant to grow from. Popular spots include the back corner, clipped to the side, or nestled in the filter compartment if there’s a lid.
4. Secure the Cuttings. Place the cuttings in your chosen holder. Ensure the nodes are submerged in the water, but keep the leaves well above the waterline.
5. Wait for Root Growth. Place your tank in its normal location. Within 1-2 weeks, you should see white, fuzzy roots beginning to grow from the nodes into the water.
6. Monitor and Maintain. As the pothos grows, you may need to trim it to keep it managable. You can also add more cuttings for greater nitrate removal.
Important Safety Considerations
While pothos is excellent for nitrate control, there is one crucial thing to remember. Pothos plants are toxic if ingested. The leaves contain calcium oxalate crystals.
* The Risk: The plant parts above water are toxic to cats, dogs, and humans if chewed or eaten. For your aquarium, the main concern is if you have plant-eating fish or creatures like goldfish or certain snails that might try to eat the roots or any leaves that fall in.
* The Reality: In practice, most fish ignore the tough roots. The toxicity is primarily an issue for terrestrial animals. However, it’s vital to be aware and take precautions if you have curious pets. Always wash your hands after handling the plant.
Maximizing the Nitrate-Removal Benefits
To get the most out of your pothos filtration system, a few simple tips can make a big difference.
* More Roots, More Removal: The greater the root mass in the water, the more surface area there is for nitrate absorption. Don’t be afraid to let a dense root network develop.
* Provide Adequate Light. While pothos survives in low light, it grows faster and consumes more nutrients in bright, indirect light. A spot near a window or under a room lamp is perfect.
* Combine with Other Plants. For a comprehensive approach, use pothos alongside fast-growing aquatic plants like hornwort or water sprite. They’ll consume nutrients from different parts of the water column.
* Don’t Stop Water Changes. Pothos is a supplement, not a replacement, for regular maintenance. You still need to perform partial water changes to remove other pollutants and replenish essential minerals.
Troubleshooting Common Issues
Sometimes, things don’t go perfectly. Here’s how to handle common problems.
* Yellowing Leaves: This is often a sign of too much direct sunlight, which can scorch the leaves. Move the plant to a spot with gentler, indirect light. It could also indicate a nutrient deficiency elsewhere, but that’s rare in an aquarium setting.
* Slow or No Root Growth: Be patient. Some cuttings take longer. Ensure the nodes are definitely underwater. If after three weeks nothing happens, try a fresh cutting from a different part of a healthier plant.
* Algae on Roots: Algae can sometimes grow on the submerged roots. This is normal and not harmful. You can gently swish the roots in old tank water during a water change to clean them off if it becomes excessive.
* Melting Leaves: If a newly submerged leaf starts to rot, you probably missed removing it. Just pluck it out of the water immediately to prevent ammonia spikes.
The Long-Term View: Maintenance and Pruning
Your pothos will eventually become a large, lush vine. A little maintenance keeps it beneficial and attractive.
Prune the vines back to your desired length. You can actually replant these cuttings right back into your tank to increase your nitrate-removal capacity or start new plants for other tanks. Simply cut below a node and repeat the setup process. Regular pruning encourages bushier growth near the tank, which can look more appealing than one long, straggly vine.
Over many months, the root system can become very dense. This isn’t a problem for filtration, but it might block flow or take up too much swimming space. During a water change, you can trim some of the roots back by up to one-third if needed. They will grow back quickly.
FAQ Section
Q: Can pothos completely replace my aquarium filter?
A: No, absolutely not. Pothos only helps with nitrate removal. Your mechanical and biological filter is still essential for removing solid waste and hosting bacteria that process ammonia and nitrite.
Q: Will pothos lower other nutrients besides nitrates?
A: Yes, it will also absorb phosphates and other dissolved compounds from the water, helping to further starve algae and improve overall water quality.
Q: Is it safe for all types of fish?
A: For most community fish (tetras, guppies, bettas, cichlids) it is very safe. Use caution with species known to nibble on roots, like some goldfish or large cichlids. Observ your fish’s behavior initially.
Q: How many pothos plants do I need for my tank size?
A: There’s no strict rule, but a good starting point is one healthy cutting per 10 gallons of water. You can always add more later based on your nitrate test results.
Q: Can I just fully submerge the whole pothos plant?
A: No, you cannot. Pothos is not a true aquatic plant. If fully submerged, the leaves will eventually rot and die. Only the roots and stem should be in the water; the leaves must be in the air.
Using pothos in your aquarium is a smart, natural, and highly effective strategy for maintaining healthier water. It reduces the frequency of water changes needed and creates a more stable ecosystem for your aquatic pets. With minimal cost and effort, you gain a beautiful, growing testament to a balanced tank. Give this method a try and test your nitrate levels over the following weeks—you’ll likely see a noticeable and welcome difference.