Can Pothos Lower Nitrates in Your Fish Tank?

Popular as a houseplant, the pothos can be grown both in soil and in water. More so, pothos can be grown in an aquarium too, where it’s often used as an aquarium plant.

The reason why pothos plants make good aquarium plants is due to their ability to act as a biological filter.

That’s right, you can use a pothos plant to lower nitrate levels in your fish tank. In fact, pothos plants can even outperform other aquarium plants in removing nitrates from your aquarium.

The reason? Simply put: Pothos plants have a fast growth rate and use up higher levels of nitrates compared to other aquarium plants.

If you’re curious about the pothos’ ability to remove nitrates, I encourage you to read this article on how you can use the pothos plant as a biological filter in your fish tank.

How Long for Pothos to Lower Nitrates from Fish Tank?

Elevated nitrate levels in a fish tank is dangerous to the delicate ecosystem within a tank, so removing it through aquarium filters or with the help of aquarium plants is necessary to prevent your fish from getting sick.

A pothos plant can lower the nitrate levels in your aquarium in as quickly as 4 to 5 days. And the expected level of reduction can range from 20 ppm to 40 ppm.

My tap water is already abundant in nitrates as it is, so adding pothos plants to my aquarium has proved a very useful tool in keeping nitrate levels under check.

Beyond this beneficial trait of pothos, they also absorb carbon dioxide and release oxygen into the tank.

Pothos are also known to remove and inhibit the growth of algae in your tank, another great perk for aquariums prone to quick algae growth.

Can Pothos Remove All Nitrates from Water?

Pothos plants are very adept at removing not only significant amounts of nitrates from your water, but also nutrients that are otherwise necessary for your fish.

This can become an issue, especially when the pothos is becoming larger and in need of more and more nutrients to sustain its growth.

If grown too large, it can very well absorb all nitrates and nutrients from your water, so make sure you’re only using pothos plants in large aquariums with lots of fish that will provide lots of nitrates to absorb.

Likewise, you may also need to add liquid fertilizer designed for aquariums to the tank to prevent malnutrition in your fish.

Can Pothos Live in Aquarium Forever?

Yes, pothos plants have a lifespan that can extend over the course of a couple of decades, so technically your pothos can live in an aquarium for as long as it receives nutrients to sustain its development.

Can Pothos Grow Under Water?

Pothos plants can live underwater for a while, however, I don’t recommend submerging the plant into the tank.

The growth will be precarious, not to mention that you open the way for possible rotting at the leaf level.

You can harvest the most benefits of the pothos plant by allowing only its roots to be submerged into the water.

The leaves should be kept above the water line to prevent them from rotting and causing problems in your tank.

You should also remove any leaves fallen into the tank for the same reason.

Is Pothos Safe for Fish Tanks?

Pothos plants will not harm your fish if you take care not to submerge any leaves in the water.

The plant grows strong roots that your fish can use as cover to hide or even lay eggs.

The roots can grow quite large and quickly overtake your tank, so trimming the roots may become necessary, just make sure not to cut all the roots to allow the plant to absorb nutrients from the tank.

How to Grow Pothos in Fish Tank?

Pothos adapt excellently to being grown in water, so the unconventional ‘substrate’ (i.e. the aquarium) will not cause any problems for the plant.

Here are the steps needed to grow a pothos plant in your freshwater tank:

– If you have a pothos plant, you can take a few cuttings and root them in water

Root cuttings in a glass jar until they establish roots. Don’t place the cuttings in the tank immediately after they’ve been cut off from the mother plant to prevent the sap leaching into the water.

The sap of the plant is toxic and can harm your fish. You can prevent this by allowing the cutting to root in a separate container.

– Anchor the plant over the tank

Once the roots are established, you can move the plant to the tank, but do so without submerging its leaves.

Once the plant is large enough and extends, it can provide an excellent cover for your tank that is both functional and aesthetic.

– Offer good lighting

Although it will adapt to low light conditions, the pothos thrives in bright, indirect light. Where enough light isn’t available, providing artificial light can help the plant grow.

– Maintain the temperature in the preferred range

Pothos will grow in temperatures between 60-80 F. Try to maintain this temperature in the room where you keep your pothos.

Cold drafts or excessive heat will cause temperature shock, stunt the growth of the plant or lead to other issues such as leaf loss.

– Don’t worry about fertilizing

One of the greatest perks of growing pothos in an aquarium has got to be the fact that you don’t have to bother with fertilizing the plant or changing its potting mix. A large aquarium with plenty of fish will provide plenty of fertilizing for the plant.


So there you have it, Mother Nature’s own aquarium fertilizer — the pothos plant. If you struggle with keeping nitrate levels low or inhibiting algae growth, pothos plants can be an excellent aide in both of these areas.

Just make sure to keep the roots at an acceptable size and keep the leaves out of the tank. Your pothos will thrive in an aquarium and your fish will be thankful for the healthy ecosystem it helps create.

Pothos   Updated: April 2, 2022
avatar Hi, I'm Amy, a devoted horticulturist and the creator of, where I use my expertise to help beginners foster their green thumbs. My blog is a vibrant community where I unravel the complexities of gardening and share my profound love for nature.
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