Pothos grows in aquariums by rooting in water while the leaves stay above the surface

Pothos is a vine plant that thrives partially submerged in aquarium water. The roots absorb nutrients from the fish waste in the tank, while the stems and leaves grow upward and out of the water. You plant it by anchoring the stem to the aquarium rim or substrate, letting the roots dangle into the water. The plant filters the water as it grows, and you get a living decoration that requires almost no maintenance beyond occasional trimming.

The setup works because pothos naturally tolerates both wet roots and dry air. Unlike most aquatic plants, it does not need to be fully submerged. This makes it one of the easiest plants to add to an established tank without disrupting the fish or the water chemistry.

Key Takeaways

  • Pothos roots grow into the water to absorb nutrients from fish waste, while leaves and stems grow upward in the air above the tank.
  • You can anchor pothos to the rim of the aquarium, a piece of driftwood, or a rock using fishing line, plant weights, or by tucking the stem under the hood.
  • A healthy pothos cutting should have at least two to three nodes (the small bumps on the stem where roots emerge) submerged in water.
  • Pothos grows fastest in tanks with bright indirect light and warm water between 65 and 80 degrees Fahrenheit.
  • Trim the vines every few weeks to prevent them from overgrowing the tank and to encourage bushier growth.

Choosing a pothos cutting and preparing it for water

Start with a healthy pothos cutting from a houseplant or nursery. The cutting should be at least 6 inches long and have at least three to four leaves. Look for a stem with visible nodes — the small bumps or ridges along the stem where roots will emerge. These nodes must be underwater for the plant to root successfully.

If you are cutting from an existing pothos plant, use clean scissors or pruning shears and cut just below a node. Remove any leaves that would sit below the waterline; submerged leaves rot and foul the water. Leave the upper leaves intact — they will photosynthesize and keep the plant alive while roots develop.

You can place the cutting directly into the aquarium, but many aquarists let it root in a small cup of water for one to two weeks first. This step is optional but gives you a chance to see roots form before committing to the tank. Once you see white root nubs emerging from the nodes, the cutting is ready to move into the aquarium.

Anchoring the pothos to your aquarium

Pothos needs to be held in place so the roots stay submerged and the stem does not drift. The most common method is to tuck the stem under the aquarium hood or light fixture at the rim. This works if your hood has a gap or if you can rest the stem in the corner where the hood meets the tank wall. The weight of the hood holds the stem in place without any tools.

If your hood does not have a suitable gap, use fishing line to tie the stem to the rim. Wrap the line loosely around the stem (not tight enough to crush it) and tie it to the aquarium frame or hood. The line is nearly invisible and holds the plant securely without damaging the stem.

Another option is to anchor the cutting to a piece of driftwood or a smooth rock using a plant weight or by wrapping it with fishing line. Place the weighted object on the substrate so the roots dangle into the water column. This method works well if you want the pothos to grow along a specific part of the tank.

Positioning the roots and leaves correctly

The key to success is keeping at least two nodes submerged while the leaves stay above water. Position the stem so that the lower 3 to 4 inches sit below the waterline and the upper leaves are in the air. The roots will grow downward from the submerged nodes and spread into the water; the leaves will grow upward and eventually trail over the rim or along the hood.

Make sure the submerged portion of the stem does not touch the substrate or get buried in gravel. Pothos roots need access to the water column to absorb nutrients and oxygen. If the stem is pressed against the bottom, it may rot instead of rooting.

Check the positioning after 24 hours. The stem should be stable and not drifting or tilting. If it shifts, adjust the anchor point or tighten the fishing line slightly. Once roots appear (usually within one to three weeks), the plant will be more stable.

Light and temperature conditions for pothos growth

Pothos grows best under bright indirect light. If your aquarium has a standard light hood, that is usually enough. The plant does not need special grow lights, but it will grow faster and fuller under stronger light. Aim for 8 to 10 hours of light per day, which matches most aquarium lighting schedules.

Keep the water temperature between 65 and 80 degrees Fahrenheit. Pothos tolerates cooler water than tropical fish, so it works in both warm and cool tanks. If your tank is heated for fish, the pothos will thrive at that temperature. In unheated tanks, pothos still grows, just more slowly.

The air temperature above the tank should be between 60 and 75 degrees. Pothos leaves are sensitive to cold drafts, so avoid placing the tank near a window in winter or near an air conditioner vent. If the leaves turn yellow or brown, check for temperature swings or cold air exposure.

Feeding the pothos with fish waste and water changes

Pothos does not need fertilizer in an established aquarium. The fish waste provides nitrogen, phosphorus, and potassium — the three nutrients the plant needs most. As the roots absorb these compounds from the water, they also help filter the tank, reducing nitrate buildup that can harm fish.

If your tank is new or lightly stocked, the pothos may grow slowly at first because there is not enough fish waste to feed it. Once the tank matures and the fish population stabilizes, growth will accelerate. You can speed this up by feeding the fish slightly more, but be careful not to overfeed, which fouls the water.

Continue your normal water change schedule. Pothos does not change how often you should change the water. In fact, the plant helps reduce the need for frequent changes by consuming some of the nitrogen compounds that accumulate between changes.

Trimming and managing pothos growth

Pothos grows quickly once it roots. Trim the vines every two to four weeks to keep them from overgrowing the tank and shading the fish. Use clean scissors and cut just above a leaf node. The plant will branch at that point and grow bushier instead of just getting longer.

You can trim the vines as short or as long as you like. Some aquarists let them trail over the rim and down the outside of the tank for a natural look. Others keep them pruned short so they stay contained. The trimmings can be rooted in water and planted in other tanks or in houseplant soil.

If a vine grows into the filter intake or gets tangled in equipment, trim it back when ready. Pothos stems are tough and can clog filters or get caught in moving parts. Check the tank weekly for any vines that are in the way.

Common problems and how to fix them

The most common issue is rotting stems. This happens when the submerged part of the stem is buried in substrate or when leaves are left underwater. The fix is to reposition the stem so it sits in open water and remove any submerged leaves. If the rot has spread far up the stem, cut off the rotted section and re-anchor the healthy portion.

Slow or no growth usually means the plant is not getting enough light or nutrients. Move the tank to a brighter location or increase the photoperiod to 10 to 12 hours per day. If the tank is new, wait a few weeks for the nitrogen cycle to establish. If growth is still slow after that, the fish population may be too small to produce enough waste; adding a few more fish or feeding more generously can help.

Yellow or pale leaves indicate low light or nutrient deficiency. Increase the light first. If that does not help, the tank may be understocked. In rare cases, you can add a small amount of all-purpose aquarium plant fertilizer, but this is usually not necessary in a fish tank.

Frequently Asked Questions

Can pothos live fully submerged in the aquarium?

Pothos can survive fully submerged for a short time, but it will not thrive. The leaves need air to photosynthesize efficiently, and the plant will eventually weaken and die if kept underwater permanently. Always keep the leaves and upper stem above the waterline.

How long does it take for pothos roots to grow in the aquarium?

Roots usually appear within one to three weeks. You will see small white bumps forming at the nodes under the water. Full root development takes four to six weeks, after which the plant will grow noticeably faster and become more stable in the tank.

Will pothos hurt my fish or plants?

Pothos is not toxic to fish and does not release harmful chemicals into the water. It will not harm other aquatic plants. The only concern is that fast-growing vines can shade slower plants or get tangled in delicate stems, so trim it regularly if you have other plants in the tank.

Can I use pothos in a tank with shrimp or snails?

Yes. Pothos is safe for shrimp, snails, and all other invertebrates. Shrimp and snails may graze on the roots or nibble the leaves, but they will not damage the plant significantly. The plant provides extra surface area for beneficial bacteria and can help filter the water in shrimp or snail tanks.

What should I do if the pothos grows too large?

Trim it back to the size you want. Cut the vines at any point above a leaf node, and the plant will branch and grow bushier. You can trim pothos as often as you like without harming it. The trimmings root easily in water and can be planted in other tanks or in soil.