11 Best Low Light Plants for Aquaponics 2023 [Updated]
If you enjoy caring for fish and cultivating plants, you can blend these passions by experimenting with aquaponics. A combination of aquaculture and hydroponics, this seemingly modern practice was first recorded as a sustainable farming technique in 1150 AD! With today’s technology, an aquaponic system can effortlessly be designed with limitations such as space and light in mind.
Light is a major limiting factor for both indoor and outdoor aquaponics. To achieve desirable natural light levels, setups need to be placed in a fully exposed area. A few hours of daylight through a south-facing window, which usually receives the most intense rays, seldom makes the cut for rapidly-growing herbs. In industrial-grade, vertical aquaponics setups, high-spectrum LED lights are used to give each plant the minimum energy requirements for growth.
If you intend to grow just a few herbs for use in your own home, investing in the proper lights may not be an economical option. Instead, you might wish to select species that can withstand low-light conditions (6 hours of sunlight or less per day). This way, you get to have low-maintenance plants that can efficiently play their role as nutrient absorbers. Simultaneously, they would be producing foliage with benefits that go beyond aquaponics.
1) Peppermint (Mentha x piperita)
This mint hybrid is one of the best herbs to grow in low-light conditions as it thrives best under partial sun exposure. A cross between M. spicata and M. aquatica, it is one of the hardiest types of mint. It can easily survive in a wide range of aquaponic conditions, including those in the most basic of indoor setups. Three to four hours of direct sunlight per day are acceptable but do note that a few more hours of daylight should strengthen the flavor of the leaves.
Peppermint should be grown in moderately warm and stable temperatures. It is an ideal species to situate alongside fish that prefer slightly acidic pH conditions (5.5 – 6.5). In the absence of waste-producing fish, a media bed, nutrient film, or liquid nutrient solution should help maintain the plant’s stability and encourage rapid growth. Over time, a healthy plant should grow to a minimum of 30 cm (12 inches), at which point its leaves can be harvested in small increments.
2) Spinach (Spinacia oleracea)
Often associated with vitamin K, which is highly concentrated in its raw and mature leaves, spinach is an internationally important herb due to its culinary and medicinal uses. Popeye’s source of strength, this miracle herb makes for a great addition to both hydroponic and aquaponic systems. Though it would grow best under full sun conditions, it is highly tolerant of partial shade.
Aim to expose spinach to at least 6 hours of direct light per day. The additional light from bulbs that are switched on at night may help supplement the plant with more energy. If direct daylight hours are limited to just 4 – 5 hours, focus on optimizing water conditions to keep the plant’s root system healthy. You should begin to have baby spinach in no time.
Though spinach can successfully be grown indoors, do note that the lack of light exposure may increase the bitterness of its leaves. Overexposure to warm temperatures may lead to this (‘bolting’) as well. In low light, it may perhaps be best to grow this species solely for the benefits it can provide the aquaponic system instead of for its use in the kitchen.
3) Arugula (Eruca vesicaria)
Also known as ‘garden rocket’, this annual herb is a widely grown crop. Its rich nutrient profile, ease of growth, and tart flavor have led to increased demand. As a result, it is now cultivated in many indoor hydroponic facilities around the world. Although its fastest rates of growth are observed under full sun or exposure to LED lights, it can survive in low natural light conditions (5 – 6 hours or less per day). Just keep in mind that reduced and partial light exposure will lead to a slower growth rate.
Although arugula is a cool season plant, it can be grown in aquaponic setups all-year round. Its tolerance for partial sunlight is increased when it is rooted in moderately warm water temperatures. Its compact roots allow for dense planting arrangements, which means a small setup should ideally support multiple specimens of the plant.
To maximize the effects of limited light, rotate your arugula plants regularly. This should encourage a more uniform rate of growth. Note that excessively warm conditions can also cause bolting, so it would be best to match this plant with freshwater fish species that favor a temperature range of 50 – 65˚F (10 – 18˚C). If you intend to consume the leaves, make sure to harvest them before blooms are produced.
4) Spider plant (Chlorophytum comosum)
If there’s any indoor plant that can beautifully settle into and continuously thrive in an aquaponic setup, it’s the spider plant! This fantastic species is remarkably hardy and versatile. If you’re new to growing plants in water or under low-light conditions, this is one of the best species with which to practice. A rapid grower, it benefits from the nutrient-rich waters in aquaponic systems.
Spider plant can be propagated from its ‘plantlets’; the young roots of these can tolerate being fully submerged. Given the consistent input of nitrogen from fish waste, they’ll quickly lengthen in well-aerated tanks. In terms of light, this species can remain perfectly content in shade or partial sun exposure. Even its variegated cultivars can persist under low light.
To ensure that the leaves remain in good shape, make sure they are kept clear of water. It’s best to use a floating or secured tray to keep the plant from tipping over. Regularly remove any decaying parts of the roots or shoot. If these are left in the aquaponic system, they may invite parasites and diseases.
5) Snake plant (Dracaena trifasciata)
Known for the snake-like appearance of its gracefully curved and upright foliage, the snake plant is one of the toughest plants for low-light cultivation. It can survive in near-darkness for brief periods at a time and can easily persist close to windows receiving just 2 – 6 hours of sunlight a day. Considered semi-succulent, it thrives best in arid substrates. It can also thrive in aquaponics systems if only its roots and crown are exposed to water.
Snake plant is best introduced into an aquaponic system in the form of healthy cuttings. Allow the base of the cut leaves to sit in a few centimeters of water. These should gradually produce new roots, which initially appear as white growths along the bottom edges. They can eventually be moved into more elaborate and complex setups with fish, but keep in mind that only the rooted base should be kept wet.
Already low-maintenance when grown in substrates, the snake plant would require even less care in water. As its leaves mature and lengthen, they should not only aid in removing excess nutrients from water but also help purify indoor air of toxins.
6) Chinese money plant (Pilea peperomioides)
As the delicate leaves of the Chinese money plant tend to scorch under bright light, they are best situated in areas that receive partial, filtered, or low-light conditions. Commonly referred to as the UFO plant or pancake plant, this species is distinguished by its circular leaves which are borne on lengthy and delicately arching petioles. Each of the leaves can measure as wide as 10 cm (4 inches) at maturity.
Partial to shaded and damp areas in the wild, P. peperomioides is naturally suited to being rooted in water. In temperatures of 10˚C (50˚F) and up, its roots gradually lengthen to accumulate higher rates of nutrients. Note that it cannot survive and produce new leaves if the water does not provide its minimum nutrient requirements. In the absence of waste-producing fish, make sure to add fertilizer to your setup.
Young specimens of this species become root-heavy a few weeks after introducing them into water (especially if the water is brightly lit). This is normal, and new leaves should soon follow if growth conditions are optimized. Try to keep the older leaves from dipping into the water as their edges may rot.
7) Devil’s ivy (Epipremnum aureum)
This tropical vine has a knack for thriving in just about any mild to warm environment with ample nutrient concentrations. It is, by far, one of the fastest-growing plants among all common houseplant species. Able to persist in relatively low-light conditions, it can be cultivated as a potted plant or grown in water. A large portion of the plant, leaves and all, can even be left submerged. In clean and well-aerated water, new roots will quickly emerge from the nodes of the shoot.
Due to the readiness of its stems to produce aerial roots, it can easily be grown via cuttings from mature shoots. To stabilize cuttings on the water’s surface, place them in a perforated tray or secure them to the edge of the tank. As they grow, they’ll absorb excess nutrients from the water. Nitrates are necessary for this species’ rapid growth.
As it matures and produces new leaves, its emergent shoots should cleanse the air of common indoor pollutants. If they are given the space and freedom to grow freely, this species’ tough stems can grow to 40 feet (12 meters) long and twine around the shoots of other plants. They will eventually arch over the tank’s edges if they are not cut back regularly.
8) Peace lily (Spathiphyllum spp.)
Several common Spathiphyllum species go by the common name of ‘peace lily’. These tropical perennials are known for their unique inflorescences, which come in the form of highly textured spadices protected by creamy-white to yellow-green spathes. These drastically contrast the appearance of the deep-green and glossy leaves.
Despite the genus’ preference for warm and humid conditions, peace lilies can easily thrive in shade and with minimal water. They can even be placed in dark corners of the home, where they can significantly brighten up the space. Throughout their native range, they are frequently used as indoor plants in office buildings and shopping centers.
As bright light can scorch peace lily leaves, an aquaponics system in a low-light environment would be ideal. These plants can survive for more than a decade in a well-kept tank setup where nutrients are frequently provided via uneaten fish feeds and waste. Their uptake of nutrients aids in keeping the water clean and controlling algal populations. Small fish can be directly exposed to peace lily roots, around which they may hide and seek shelter.
9) Arrowhead vine (Syngonium podophyllum)
Named for the arrow-like shape of its eye-catching leaves, this plant is the most popularly grown Syngonium species. Now naturalized in some parts of the US, it favors warm, forested regions where its trailing stems can climb and cling to the trunks of tall trees. Wild arrowhead vines usually have dark leaves and minimal variegation, whereas those propagated and sold for indoor use tend to have cream-colored markings over a lighter green base.
A recipient of the RHS Award of Garden Merit, this fine houseplant is one of the best choices for low-light areas. In fact, it is not suitable for growth in areas receiving bright, intense light because its leaves have the tendency to get sunburned or bleached. Partial or diffused light is best, but do note that less sun exposure may cause the foliage to turn a deeper green.
Cuttings of the arrowhead vine can easily be propagated in soil or water, especially if they already have aerial roots. They are more likely to send out new roots and produce leaves if nutrients are readily available for absorption.
10) Chinese evergreen (Aglaonema spp.)
Chinese evergreen comes in dozens of vividly-colored cultivars and a wide range of sizes. With species that may be called Malayan sword, poison dart plant, lily of China, and spotted evergreen, it becomes a quick favorite of just about anyone with a passion for growing houseplants.
The leaves of this species are perfectly suited for indoor locations, where they can effectively brighten up dim spaces. They are prone to becoming scorched under direct light. As Aglaonema species can be rooted in water, they can be cultivated in an aquaponic system. Just keep in mind that, although the leaves can appear fleshy and harmless, they are not safe to eat. Filled with calcium oxalate crystals, the juices of this plant can cause irritation upon skin contact and when consumed. If your fish have the tendency to nibble on roots or foliage, it may be best to place this plant in a separate tank.
11) Chives (Allium schoenoprasum)
One of the most ideal herbs to grow in shaded areas, chives are a valuable perennial with a widespread distribution. They are closely related to garlic, scallions, leeks, and onions, all of which have benefits that extend far beyond the garden. Though it is a winter hardy species, it is small and compact enough to be grown indoors through the seasons.
Under low light, chives may have a slower rate of growth and may fail to bloom. However, they will still continue to produce new leaves. This wonderful plant can be cut back to 1 – 2 inches or 2.5 – 5 cm above the crown regularly or whenever the kitchen calls for fresh produce. After a few days to weeks, mature plants will usually begin to produce foliage once more. Some people even opt to place their sprigs of purchased chives (with intact roots) in water as soon as they get home from the market.
As an herb that is frequently cultivated using hydroponic methods, chives are invariably suitable for aquaponic systems. To enhance the quality of the leaves, make sure the water temperature is maintained at 18 – 27˚C (65 – 80˚F). A slightly acidic pH should help the plant absorb excess nitrates in the water.