Skip to content

Many people know of pothos as a hardy houseplant, but its also popular among fishkeepers for use in sumps, overflows, hang on back filters, refugiums, and aquariums. Adding a pothos plant to your aquarium is a good way to reduce nitrates and give it a more natural look.

Buy Pothos on Amazon

Fish waste (ammonia) is transformed into nitrates by the bacteria in your filter. Nitrates are harmful to fish and need to be removed from the aquarium, typically through water changes. In nature, plants perform this function by absorbing nitrates. While a single pothos plant will not absorb enough waste for you to skip any water changes, it will help to reduce these excess nutrients.

Pothos Growing up PVC
Pothos vine Growing up PVC

How to add Pothos to Your Aquarium

You can find pothos (in the US) for sale at most local garden centers, any store that carries houseplants, or on Amazon. Once you've purchased a plant, you can either add the whole plant to your aquarium - after removing it from the soil - or take cuttings from it. One healthy mother plant can produce dozens of cuttings. I have been taking cuttings from the plant shown below for several years. The vines eventually grow back after being cut.

Pothos Plant
Pothos Plant

Pothos is also known as devil's ivy because it is so difficult to kill. The stem can be cut and inserted directly into water. After a few days, white roots will sprout from the stem and grow down into the water. This works even in a glass of tap water, but pothos plants grow much quicker in an aquarium where they have access to lots of nutrients.

Pothos does not require much light to grow, so you don't need to have a light shining directly on it unless you have it under a cabinet or in some other very dark location. The leaves will turn to face any nearby light sources as the plant gets established.

Pothos growing behind matten filter
Pothos growing behind matten filter

I secured the plant pictured above using a suction cup with a clip for airline tubing. This is a good way to hold the vine in place inside your aquarium. You can also insert a stem into a hang on back filter, an overflow or breeder box, or build your own DIY container to hold pothos plants.

Pothos roots in overflow box
Pothos roots in overflow box
Pothos roots in overflow box
Pothos roots in overflow box

More Info on Pothos in Aquariums

There are lots of examples on YouTube of how people are using Pothos in their aquariums. I recommend starting with the one below from Aquarium Co-op.

Odin Aquatics isn't affiliated with any YouTube channels

Seachem Purigen is a synthetic absorbent that captures organic waste in the water column. It can absorb and trap nitrogenous organic wastes that would otherwise release ammonia, nitrite, and nitrate. Tannins from driftwood and other natural decor in the aquarium are also captured. Eventually, Purigen will turn dark brown to black, as shown in the photos below. But you don't have to discard it and buy more at this point, because Purigen can be regenerated and reused!

Used Purigen Bags
Used Purigen Bags

The Purigen packet on the left in the above photo was used for just a few weeks in an aquarium with some large pieces of driftwood. The brown color is due to it absorbing tannins from the wood in the water. The packet on the right was used in a different aquarium for several months.

Recharging Seachem Purigen

Basic directions for re-charging Purigen are available on Seachem's website. A screenshot of their instructions is included below:

Seachem Purigen Regeneration Instructions
Seachem Purigen Regeneration Instructions

Bleaching Purigen

I recharged two 100 ml bags of purigen using a solution of 2 cups Clorox bleach and 2 cups water in a plastic container. The bleach burns off organic material that has been captured by the Purigen. You can see the brown and green coloration was completely removed from these two bags after 24 hours.

Bleached Purigen Bags
Bleached Purigen Bags

Dechlorinating Purigen

After soaking for 24 hours in the bleach solution, I mix a solution of 2 cups tap water and 1 TSP of Seachem Safe. Safe is the same thing as Prime, but it comes in a dry powder form and 250 grams treats up to 60,000 gallons. Compare that to a 500ml bottle of Prime, which treats only 5,000 gallons. Per Seachem's instructions, you can use any equivalent dechlorinator, just be sure to use a large enough dose to remove all chlorine.

"<yoastmark

This is the first time the packets shown have been regenerated. After multiple uses, Purigen will begin to show staining or discoloration. I don't recommend re-using it more than 3 or 4 times.

Buy Seachem Purigen on Amazon

Mechanical Filter Media Basket
Mechanical Filter Media Basket

This mechanical media basket holds filter floss pads and Polyfil where water enters the sump on my 90 gallon rainbowfish aquarium. It is made from a plastic tupperware container that I up-cycled from a package of lunch meat (after washing thoroughly). I drilled about 30 holes into the bottom of the container using both a 1/8" and 1/4" bit to spread the flow evenly across the tray.

This is a modification to the original design for my DIY 20 gallon sump. The container fits perfectly into the larger basket that houses a coarse sponge and previously held my mechanical media. A smaller media tray keeps the flow of water concentrated into a reduced surface area, which allows me to use less mechanical media. It also facilitates changing the media, because it is easily removed and replaced, as shown in the video below.

The bottom of the basket is stuffed with Polyfil which is then covered by a piece of filter pad media that is cut slightly larger than the aperture of the container. The clear sides allow me to see when the media is dirty and needs to be changed. This is a dirt cheap DIY  mechanical filtration solution for a sump; I covered the use of Polyfil and some other cheap DIY filtration solutions here.