The Best House Plants for Aquaponics 2023 [Updated]
Cultivating houseplants is fun, educational, extremely rewarding, and highly beneficial for home hygiene. Plants aid in the removal of toxins from trapped air while bringing natural color and texture to indoor spaces. Growing them in soil is generally ideal, but this can lead to root rot and pest or mold production in unfavorable conditions. The good news is many houseplants can be rooted in water instead, and their nutritional needs can be met using simple aquaponic techniques!
An indoor aquaponics system is essentially a closed water circuit sustaining the needs of both plants and fish. In theory, it is a biologically ingenious and highly sustainable approach to providing the basic requirements of two very different forms of life. The plants, which need nutrients to grow and thrive, filter waste out of the water. The water is then made more suitable for fish, which produce nutrient-rich waste.
The best plant species for indoor aquaponics are those that are able to tolerate low light levels and require minimal care. Those with root systems that can thrive in moist to wet soils are generally the best candidates. This method of growing plants eliminates the need for regular watering schedules, fertilization, and the mess of dealing with potting soil. A thoughtful selection of houseplants should keep your tank running efficiently while adding decorative elements to your home.
1) Pothos (Epipremnum aureum)
Pothos, or devil’s ivy, is truly one of the most popular houseplants as it is remarkably easy to grow and care for. With their creeping habit, pothos stems can grow to impressive lengths and trail from balconies, staircases, wall fixtures, or along the sides of an aquarium. Their heart-shaped leaves are naturally variegated with lovely white, yellow, or gold speckles and stripes. Roots are rapidly generated along the nodes of each stem, so divisions can easily be propagated.
This species is, by far, one of the fastest-growing low-light plants. Mature plants that are fully-rooted in water may need to be cut back regularly to prevent their roots from outgrowing the entire tank! Pothos, regardless of its variety, provides a wealth of benefits to aquaponics systems or aquariums. It can act as a living filter for removing considerable amounts of nitrates from the water. It competes with algae and thereby reduces algal growth.
If the pothos roots and submerged stems are allowed to directly come in contact with fish, they provide high structural cover and protection. Fry and small fish can hide behind the roots as potential predators lurk around the tank. One important thing to note: exposed pothos tissues may be toxic due to their calcium oxalate contents. Allow cuttings to heal in a separate container before moving them into the main tank.
2) Peace lily (Spathiphyllum spp.)
Known for their specialized inflorescences, which are distinguished by a white to green spathe surrounding a textural spadix, peace lilies are perfect for indoor settings. Though they are generally terrestrial plants that thrive best in terrarium-like settings, they can be cultivated in an aquaponic setup as well.
To root peace lilies in water, their shoots and leaves should not be submerged. The base of the shoot may be elevated and held in a separate container so that the leaves are kept dry. A perforated cup with a stopper to hold the crown of the plant should work well. The roots, which should be fully submerged to prevent them from drying out, will naturally elongate in the water.
Apart from being efficient at nutrient removal, peace lilies have long been known as purifying plants. Their fleshy foliage, which give the plant ornamental value even in the absence of flowers, are able to thrive in low light conditions if they have been acclimated beforehand. If your setup can be placed in an area that receives bright, indirect sunlight, the peace lilies are more likely to send out larger, deeply colored leaves.
3) English ivy (Hedera helix)
In search of a vine that can beautifully cascade down the sides of an aquaponic or aquarium setup? The English ivy is a trailing, evergreen perennial that’ll have you pruning its stems in no time. This rapid grower is frequently cultivated as an ornamental plant in indoor and outdoor locations. It seems to cling to just about any type of rough surface as long as its main root system is well-established.
English ivy leaves have many decorative qualities due to their unique shape and varied coloration. With over 30 cultivars and more than a dozen recipients of the RHS Award of Garden Merit, H. helix has a widespread distribution and has been naturalized in many parts of the globe. Be wary of growing this species outside of its native range as it has the tendency to become invasive.
If you intend to root your English ivy in water, make sure that only the roots are fully submerged. The stems and leaves should be kept dry as they are likely to rot if they are kept wet for extended periods of time. Note that the leaves contain toxic compounds. These may cause severe contact dermatitis when handled by people with hypersensitivity to falcarinol (also present in red ginseng and carrots). The leaves are also poisonous to mammals.
4) Heartleaf philodendron (Philodendron hederaceum)
A plant that is known for being quite difficult to kill, Philodendron hederaceum (syn. P. scandens) is a remarkably hardy tropical houseplant. Though it isn’t generally considered an aquatic plant, it favors moist substrates and can easily be propagated in water. In fact, even if the cuttings are intended for growth in a pot, they are often started in a vase or jar of water. If the leaves are exposed to bright light, new roots will quickly arise from the nodes of the partly submerged stem.
This species is a recipient of the RHS Award of Garden Merit as it is an evergreen ornamental that requires minimal care. Its heart-shaped, deep green foliage emits an eye-catching luster that signifies good health. Be wary about growing this species indoors if you have cats, as its cells contain calcium oxalate crystals, which can cause oral and digestive irritations when ingested.
To root heartleaf philodendron in water, take a 6-inch stem cutting from a mature plant. Remove the leaves from at least 2 – 3 of the lowermost nodes, which is where new roots will begin to develop. Place the cutting in a jar of dechlorinated water, and make sure to change the liquid every 2 – 3 days. The bare nodes should be fully submerged. After about 2 weeks of exposure to bright, indirect light, your cutting should have new roots. It can permanently be kept in water or transferred to a pot as soon as the roots are large enough.
5) Spider plant (Chlorophytum comosum)
Unbelievably easy to cultivate indoors, the spider plant has a knack for surviving and sending out offsets in all sorts of conditions. As long as it is kept in fairly warm conditions and exposed to ample sun, it will reward its caretaker with sprays of new leaves at a favorably quick rate.
This highly adaptable species is ideal for growing in tanks, jars, and just about any type of aquaponic system as long as its roots are submerged. The leaves should be kept dry to ensure that they remain in good condition. If kept moist for extended periods of time, the non-aquatic leaves may begin to rot. Ideally, the shoot should be propped up and placed on a tray with a hole, from which the roots may dangle into the water below.
To ensure that the spider plant’s roots are kept in good condition, the tank should ideally be aerated or planted with submerged oxygenators. The temperature should also be stabilized to prevent thermal shocks as these may compromise plant growth. Fertilizer need not be added to the aquaponic solution, particularly if there are fish in the water.
6) Chinese money plant (Pilea peperomioides)
If your aquaponics setup is in need of character, try cultivating a few cuttings of the Chinese money plant. This adorable species is set apart by its delicate, circular leaves which are borne on relatively lengthy petioles. When exposed to bright sunlight, the leaves arise in a loose spiral around the stem. Though they may resemble the foliage of some floating plants, the leaves should be kept dry. The roots, on the other hand, should remain fully submerged.
When rooted in water, the Chinese money plant will require minimal care. Best of all, you need not worry about the plant being over or underwatered as its root system will fully adapt to aquatic conditions. One of the only downsides to growing this species in water is its tendency to become root-heavy. It will likely redirect its energies to producing lengthy roots instead of more leaves. By keeping the roots in an opaque or shaded tank, while the leaves are exposed to bright light, this phenomenon can be abated.
The nutrients generated by fish waste in an aquaponic system should be sufficient enough to support the roots. Oxygen may need to be supplemented, however, as this is a requirement for healthy root growth. Note that P. peperomioides is also unlikely to produce offsets if it is grown in water. You may eventually plant the water-rooted stalk in soil if you intend to propagate it.
7) Snake plant (Dracaena trifasciata)
Incredibly hardy and perhaps the most tolerant of low light levels among popular tropical houseplant species, the snake plant can be grown and propagated in water. This beginner-friendly species is an evergreen semi-succulent. Though it thrives best in well-draining substrates and is adapted to arid conditions, its leaf cuttings can surprisingly root well in shallow water! They can also be elevated or held upright on a tray so that a larger portion of the leaves stays dry.
The main reason why snake plants can thrive in water but tend to rot in moist soil has to do with oxygenation. Perpetually waterlogged soil is poorly oxygenated and can suffocate even well-established root systems. Snake plants that are cultivated only in water are able to acquire oxygen through diffusion or supplementation. In aquaponic tanks, ample oxygen is usually provided by other plants as well.
To grow your snake plant in an aquaponic setup, you’ll need to prop up the crown of the plant on a tray. The tray can be partly submerged to bathe the base of the leaves. Pebbles can be used to keep them upright as the roots will easily grow in between the gaps of the stones. Over time, the rooted leaves will produce new offsets that will greatly benefit from the present nutrients.
8) Ferns (Tracheophyta)
Many types of ferns thrive when their roots are kept moist or wet, even in dense substrates. These plants are naturally suited to humid conditions and can grow remarkably quickly when nutrients are readily available. Hydroponic and aquaponic setups are actually ideal for cultivating and propagating ferns, which are generally thirsty plants.
Although ferns are not considered aquatic plants, they are able to thrive in water even if their leaves are partly submerged. Some species tolerate being fully submerged if the water is regularly circulated, replaced, and kept largely free of algae.
One of the most well-loved houseplants, the Boston fern (Nephrolepis exaltata), can easily be water-propagated using rooted divisions. These can be propped up into a shallow tray using a mixture of stones of varied sizes. The gaps between the stones promote oxygen diffusion and are spaces in which new roots can grow and become well-established.
9) Marigold (Tagetes spp.)
With their brightly colored floral heads, marigolds are a culturally important and highly beneficial plant to have in your own home. As they grow in almost any type of substrate, it follows that they can grow in water as well. Marigolds are considered some of the best flowering companion plants in aquaponic systems that are used for vegetable cultivation. They have natural pest-repelling properties, partly due to their strong odor.
As long as ambient conditions are optimized and nutrients are readily available, marigold stem cuttings easily root in water. Most aquaponic media should be quite effective as long as only the roots of the plant are fully submerged. The shoot should ideally be propped up by a media grow bed or in a perforated container where the roots can grow through the holes.
Marigolds prefer slightly acidic water with pH levels ranging from 5.8 – 6.2. They can strip the aquaponic system of nitrogen and phosphorus, so these nutrients must be continuously provided to prevent deficiency symptoms. Daytime water temperatures should be between 16 – 21˚C (60 – 70˚F) for the shoots to thrive and eventually produce blooms. The blooms can quickly rot in humid conditions, so deadhead them as soon as they are spent.
10) Lavender (Lavandula spp.)
Lavender plants normally favor dry conditions in temperate zones. They may be tricky to cultivate in humid regions. They can easily suffer from being overwatered, particularly when sun exposure and ventilation levels are inadequate. When cultivated in soil, drainage is extremely important as trapped moisture is bound to cause root rot. Fortunately, there is a way to eliminate growth problems associated with water stress – cultivate your lavender plants using an aquaponic system.
Lavender can be grown much like other edible herbs in an indoor setup. This eliminates unwanted pests, extreme shifts in temperature, and rain exposure. A controlled setup with stable temperature, humidity, and lighting levels works best. At least 6 hours of exposure to LED grow lights is usually sufficient to encourage rapid growth. Water pH levels should be maintained at around 6.5 – 6.8 to facilitate efficient nutrient uptake rates.
Your main purpose for lavender cultivation will determine the appropriateness of your aquaponic setup. If the plant is simply grown for ornamental purposes, you can mount the base of each stem in a floating raft or media bed. The roots will naturally grow downward and benefit from the nutrient-rich water. If you intend to grow lavender at a large scale, the NFT (Nutrient Film Technique) system may serve you best as it is made to suit a high volume of plants.