Pothos grows above water while roots feed your fish tank

Pothos is a vine plant that thrives when its roots sit in aquarium water while its leaves grow above the surface. The plant absorbs excess nutrients (nitrogen and phosphorus) that would otherwise cloud your water or feed algae, while the roots provide a natural hiding place for fish fry and small species. You hang it by anchoring the stem to the tank rim or a piece of driftwood, letting the roots dangle into the water below.

This setup works in tanks of any size, though larger tanks give you more room to position the plant without blocking your view. The plant needs light — ideally 8 to 12 hours a day from a window or aquarium light — and will grow faster in warmer water (68 to 85 degrees Fahrenheit). Unlike plants that root in substrate, pothos never needs soil, fertilizer, or special planting supplies.

Key Takeaways

  • Pothos roots absorb excess nutrients from the water, reducing algae growth and keeping the tank cleaner between water changes.
  • The plant hangs above the tank with roots submerged, so you need a way to anchor the stem to the rim or to driftwood inside the tank.
  • Pothos grows in any light level but develops faster and fuller in bright indirect light or under an aquarium lamp for 8 to 12 hours daily.
  • The plant is safe for all fish and invertebrates and actually provides shelter for fry and small species that hide among the roots.

Anchoring the stem to the tank rim

The simplest method is to rest the pothos stem across the top of your tank and find it so it does not slip into the water. Cut a notch into a piece of cork bark or foam — about half an inch deep and wide enough for the stem to sit in — and lay it across the rim. The stem rests in the notch while the roots hang down into the tank on the inside. This works best on tanks with a standard frame or rim; rimless tanks need a different approach.

If you do not have cork bark, you can use a clothespin, a small piece of plastic tubing split lengthwise, or even a rubber band looped around the stem and hooked over the rim. The goal is to hold the stem steady without crushing it. Check the anchor daily for the first week to make sure the stem has not slipped or the anchor has not loosened.

Using driftwood or a suction cup mount inside the tank

For a cleaner look, attach the pothos stem to a piece of driftwood or rock already in your tank. Tie the stem loosely to the wood using fishing line, plant weights, or soft plant ties — anything that will not cut into the stem as it grows. Position the driftwood so the stem angles upward and out of the water; the roots will grow downward into the tank while the leaves reach toward light above the surface.

Alternatively, use a suction cup plant anchor (sold at aquarium stores) attached to the inside of the tank glass. Loop the stem through the anchor and let it rest there. As the plant grows, it will naturally climb and spread, so leave slack in any ties you use. Tighten them only enough to keep the stem from falling over.

Positioning for light and water flow

Place the pothos where it receives the most light in your setup. A corner near a window works well if the tank is not in direct afternoon sun, which can heat the water too much. If your tank sits away from natural light, position the plant under your aquarium lamp or hood light. The leaves should be above the water surface and angled toward the light source.

Avoid placing the plant directly over a filter outlet or air stone, as strong water movement can damage new growth and make it hard for the stem to stay anchored. A gentle current is fine — it actually helps the roots absorb nutrients — but the plant should not be in a direct blast of water.

Caring for pothos in an aquarium

Pothos needs almost no maintenance once it is anchored. The plant feeds on fish waste and excess nutrients in the water, so you do not need to add fertilizer. Trim the stem with clean scissors whenever it grows too long or too bushy for your tank. Pinching off the growing tip (the topmost leaves) encourages the plant to branch sideways instead of growing straight up, creating a fuller appearance.

If the leaves turn yellow or brown, the plant is either not getting enough light or the water temperature has dropped below 60 degrees. Move it closer to a light source or check your heater. Brown leaf tips can also mean the stem is being crushed by the anchor — loosen it slightly. Pothos is extremely hardy and will recover quickly once the problem is fixed.

Preventing the plant from taking over your tank

Pothos grows fast, especially in warm water with good light. Trim it every two to four weeks to keep it from covering your entire tank and blocking your view of the fish. Each time you trim, the plant branches at the cut point, so you will have more stems to manage. If the plant becomes too large, you can remove entire stems at the base or propagate cuttings in water or soil to start new plants elsewhere.

Never let dead leaves or trimmings sit in the tank — remove them when ready so they do not decay and foul the water. Healthy pothos leaves are firm and green; if you see mushy or translucent leaves, cut them off and improve the light or water flow to the remaining plant.

Frequently Asked Questions

Can pothos roots clog my filter?

No. Pothos roots are soft and will not damage a filter intake. If roots grow long enough to reach a filter outlet, trim them back. The roots themselves are beneficial — they provide surface area for beneficial bacteria to colonize.

Will pothos harm my fish or shrimp?

Pothos is completely safe for all fish, shrimp, and invertebrates. Fish will not eat it, and the plant will not release toxins into the water. Fry and small species actually benefit from hiding among the roots.

How fast does pothos grow in an aquarium?

Growth speed depends on light, temperature, and water nutrients. In warm water (75 to 80 degrees) with good light, you may see new leaves every few days. In cooler, dimmer conditions, growth slows to a few leaves per week.

Can I use pothos in a betta tank or small aquarium?

Yes. Pothos works in any tank size, including 5-gallon betta tanks. In small tanks, trim it more often to prevent it from shading the fish or taking up too much space. The roots still benefit the water quality even in a small volume.

What if my pothos leaves are pale or growing slowly?

The plant is not getting enough light. Move it closer to a window or add an aquarium lamp above the tank. Pothos can survive in low light but will not thrive. Pale leaves usually turn green again within a week or two of better lighting.