Do Hydroponics Need Sunlight? (Yes, They Extremely Do)

Hydroponics is an amazing process of horticulture that involves the growing of plants, especially crops and medicinal plants, without the presence of soil.

It is grown in a water-based nutrient solution in aqueous solvents to provide mechanical support. The hydroponics process is also popular by the name of aquaculture or tank farming. This process was initiated by scientists to particularly observe the mechanism of plant nutrition.

But, do hydroponics need sunlight?

Light is a vital component of hydroponic cultivation, so hydroponic plants need sunlight to grow properly. Light is a mandatory component for the photosynthesis process of all types of plants.

Do hydroponics need sunlight (detail explanation)
Do hydroponics need sunlight?

For the plant to grow perfectly, bloom, and produce seeds, it is essential for it to be exposed to perfect sunlight. It is not possible for plants to grow completely without sunlight forever. For some time, it can cope without the photosynthesis process; however, at some point, sunlight is required.

However, sunlight is very important for hydroponics to grow properly for the photosynthesis process. But these days, there are hydroponics grow lights available with the help of which plants grown through hydroponics usually bloom. 

Do Hydroponics Need Sunlight?

The answer would be a big ‘Yes’ as sunlight plays a vital role in the hydroponics plants to grow properly. Because for plants to grow properly and prepare food, natural light is essential. Plants need light, air, water, nutrients, and sufficient space to grow properly.

There is no better source of natural light other than sunlight. However, since hydroponics is a scientific process, grow lights and led lights are an alternative to sunlight for hydroponics to grow.

Based on the plant that has to be grown through a hydroponic process, the grow light is chosen and exposed to the plant. Since hydroponics is mostly an indoor process, an appropriate light source with an exact light spectrum is important. 

Is Hydroponics Without Sunlight Possible?

Already stated above, sunlight is an important aspect of hydroponics. Simultaneously, hydroponics is a scientific process; it can be grown with the help of other sources of light apart from sunlight.

Rather the correct form and quantity of light are important for the plant to grow to its complete potential with all its qualities.

Is Hydroponics Without Sunlight Possible
Is Hydroponics Without Sunlight Possible?

However, without sunlight, there are certain challenges that are faced in the hydroponic system. Light is the main source of energy in the process of photosynthesis.

So if the plant lacks sufficient sunlight exposure, it won’t grow properly. So for hydroponics, apart from sunlight, an appropriate light spectrum is mandatory for its growth.

It is also important to identify the correct stage of the plant because, based on that, the light spectrum would be used. If the plant is in an early stage of growth, they need a light source that is hugely packed with energy.

Generally, the blue spectrum light with 400-500nm is required, and if they don’t get enough source of blue light, it will turn out to be weak with yellow streaks on the leaves rather than vibrant green streaks.

After this, once the plant comes to the flowering state, it needs a light source that has low energy. So a red light spectrum with 650-730nm is perfect during this stage for it to bloom perfectly. 

Types of Grow Light

There are different types of grow lights available for hydroponic gardening. It is important to know the exact type of light for a particular plant. 

High-Intensity Discharge (HID)

These lights have been immensely popular with indoor plants for a long time.

They have typical odd shape lights that have a hood with screws attached to it.

The light produced from high-intensity discharge lights is very intense that is used on plants at both vegetative as well as flowering stages.

However, there is one issue with HID lights, they produce excessive heat and consume too much energy.

High-Intensity Discharge (HID)
High-Intensity Discharge (HID)

Hence they are majorly preferred by commercial gardeners. They are further segregated into two types one is High-Pressure Sodium which has more red light in it, and Metal Halide contains more blue light. 



Fluorescent lights do not produce extreme heat like HID lights, but they mainly impart a blue light spectrum, so they are mainly used in the initial phase of hydroponic plants.

For the flowering stage, the fluorescent lights would require an extra red lamp for the hydroponic plants to bloom flowers.

They are extremely safe for plants.

Fluorescent lights are further segregated into two types, fluorescent tubes and compact fluorescent lights (CFL).

LED (Light Emitting Diode) lights

The LED lights are the perfect choice for both commercial as well as domestic gardeners.

They are not expensive like the other grow lights and also produce very less heat.

Hence they are considered to be absolutely safe for hydroponic plants.

And the best part is that the panels of the LED lights can be tailored for both blue and red light spectra so that there is no hassle of further addition of lights and can cater to all the plant needs.


Incandescent Grow Lights

Incandescent Grow Lights
Incandescent Grow Lights

Incandescent grow lights are considered to be the most expensive among all grow lights; however, performance-wise, they are of least efficient.

They are not at all considered to be safe for the plants as they generate excessive heat, which is dangerous for the plants as they damage them.

Therefore, they are not the ideal choice for hydroponic gardening.

Halogen Lights

Halogen lights are considered to be nearest to natural sunlight.

They are not all expensive in comparison to the other grow lights available and produce very less heat.

However, they are considered safe for plants; however, they are not as efficient as Fluorescent lights or LED lights.

Hence, they are not the ideal choice for hydroponic gardening.

Halogen Lights
Halogen Lights
Ideal for bushy herbs or plants with dense foliageIdeal for plants like cereal, citrus, forage and C4 plantsBest for seedlings, small-size plants, and clones

Lighting Requirements for Hydroponic

Photosynthesis is the process made by plants in which they combine sunlight, water, and carbon dioxide to produce oxygen and energy that comes in the form of sugar. This chemical process relies on chlorophyll which is a pigment that gives green color to the plants. 

Lighting Requirements for Hydroponic
Lighting Requirements for Hydroponic

The wavelength of light that is required for hydroponics depends on the stage of the plants. Blue light is the main source of energy that is required at the initial stage of the plant, and the wavelength of the blue color spectrum is 400-500 nm.

Red light is required at the flowering stage of the plant, and the wavelength of the red color spectrum is 630-660nm.

This wavelength is perfect for the flowers to bloom. Greenlight was considered not to be necessary for plants earlier; however, recent studies have shown proof that the wavelength of green light usually penetrates through the thick canopies and supports its leaves in the lower canopy. The wavelength of green light is 500-600nm.

The yellow-red light that has the usual wavelength of 610-700nm is considered to be the optimum wavelength for the absorption of chlorophyll, germination, and also the development of flowers and buds.

This wavelength is the ideal range for flowering and photoperiodism.

Whenever this light gets balanced with blue and green light, it converts to an ideal growth of the plant. Recent research has also declared that far-red light is important for hydroponics plant growth.

It has a wavelength of 700-800 nm, has huge benefits and also accelerates extension growth. 

On average, 32 watts of power per sq ft is required for a LED grow light for plants that are in a flowering state. In the case of HID grow lights, 40 watts of power is drawn per sq ft for an area of 5’ x 5’ and 62.5 watts of power per sq ft for an area of 4’ x 4’. 

Advantages and Disadvantages of Sunlight for Hydroponics

Sunlight is a very important component for the growth of plants. Without sufficient sunlight, the plant won’t grow properly. Now in the case of hydroponics, there are always pros and cons of added sunlight. Let us discuss those points.


Cost Effective: Sunlight always saves electricity consumption from grow lights, thereby reducing its cost.

So it is preferred to set up a hydroponic garden in an area where there is the luxury of some sunlight.

Space Utility: If there is the advantage of some sunlight in your hydroponic garden, then it will always save adding extra grow lights within the system.

Hence making room for more space that would have been occupied by grow lights.


Placement of Hydroponic Garden: Sunlight, to some extent, is always great for hydroponics; however, too much sunlight is never too good for plants.

So it is important to choose the location very effectively. The place where the hydroponic settlement is placed might be the only area where the light comes. Hence you may skip any other light option in that place.

Reliability: It should not be an ideal choice to be solely dependent on sunlight for a hydroponic garden. A commercial gardener would never do so as the sun wouldn’t shine the same every day.

Some days the weather would be cloudy and rainy and won’t be any sunlight. So it is better to grow lights as a backup option.

Advantages and Disadvantages of Using Grow Light

As sunlight also has its own pros and cons similarly, let us discuss the advantages and disadvantages of using grow lights in a hydroponics garden. 


Replica for Sunlight: In a hydroponics garden, the best alternative to sunlight is the use of grow lights. They have all the features to replicate sunlight.

If you use the correct type of grow lights, it becomes the ideal choice as they are able to cover the ideal spectrum of sun rays. They can be set with proper time as per the sun’s rays and pretty much do the same job as sunrays.

Even the heat can also be controlled based on the grow light.

Round-year Performance: The best part of grow lights is that they are not dependent on weather and sunlight.

Due to this, they provide consistent growth to different types of plants regardless of the climate of the location of the garden.

The Ideal Plant: Light and heat are the most important two aspects for the healthy growth of plants in hydroponics. Since these two can be adjusted based on the grow lights, anybody can grow their ideal plant in their hydroponic setup.

Once you understand the requirements of a particular plant, heat and light can be set perfectly every time you grow your ideal plant.


Not much cost-effective: Grow lights are definitely not a cost-effective way to grow your plants. As these lights are quite expensive and further, they would consume lots of electricity.

Moreover, these lights need to be maintained properly, which also involves an additional cost. It is also seen that many commercial gardeners sell their hydroponics setup for extra income of money.

Lights would Burn: In a hydroponic garden setup, lots of safety measures need to be undertaken.

The grow lights should not be kept extremely near to the plants, or else the plants would be affected by the light burn.

Moreover, if the correct form of light is not used during different stages of plants, then there would be a discrepancy in heat distribution which would risk a light burn.

Frequently Asked Questions (FAQs)

Do purple LED lights help plants grow?

When the red and blue diodes inside the LED light would combine together, then purple color is emitted. And the best part is these lights optimize both red and blue on the light spectrum. So they are an ideal combination for the growth of the plant as they would support all the stages.

Do seedlings need red or blue light?

Red light is the ideal color of light for the seedlings to germinate, the growth of the root, and the development of the bulb. The red color is generally used during the flowering stage when the plant blooms, flowers, and bears fruits. If there is a mix of different types of plants in the hydroponic garden and if the plants are planted beneath a thick canopy of leaves, then blue light is also required for the plant to grow properly.

How much heat do grow lights produce?

The quantity of heat that is generated from the energy sources is usually measured in BTUs. Therefore, to calculate the amount of heat that is generated from a particular lamp or a light, the quantity of watts is multiplied by 3.41. 
1 Watt of power = 3.41 BTU. 
So a LED growth light that has 500 Watts of power would produce 1.877 BTU heat per hour. 


Hydroponics gardening is an excellent way to grow your favorite plants in the most consistent way and also enjoy the fresh produces.

The best part is these gardening setups do not need too much space, don’t require extreme and critical maintenance, and also produce excellent plants with flowers and fruits.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top