Guide to Indoor Aquaponics Grow Lights

Guide to Indoor Aquaponics Grow Lights

Grow lights are an important component for indoor aquaponic gardening. Grow lights supplement the natural sunlight needed by the plants and can increase plant production by up to 40%. 

If you are growing your aquaponics plants in a greenhouse or indoors, you need to provide 100% of the light that the plants need.

This guide to Indoor aquaponics Grow Light will hopefully assist you in creating the right light setup that is suitable for your growing environment. 

Plants Need Light

Plants need light to grow. If you give them too much light, your plants will suffer and will not grow, which will only waste your electricity. However, if you don’t give them light, your plants will not grow at all, so you need to provide plants the right amount of light for them to grow. If you grow your plants indoors or in a greenhouse, choosing the right indoor light for your plants can be difficult. To choose correctly, you need to know these few things. (1)

How Much Light Do Your Plants Need?

To know how much light your plants need, think of how plants grow in its natural environment. Most vegetable plants need full sunlight, which means you need to provide a little more light to your plants in the greenhouse or indoors. You will need 30-40 watts of light per square foot of growing area, but fruiting plants and tomatoes need more light. You only need to calculate the size of your growing are not the whole room in calculating how much light you need for your plants. (1)

Signs that your plants are getting too much light.

  1. Plants leaves look droopy or dried out with curled leaf edges.
  2. Plant leaves have dead brown spots in the areas that are closest to the light.

Signs that Plants are not getting enough light.

  1. Thin uneven growth with tall spindly stems.
  2. Plants lean more towards the light.

What kind of grow light do you need?

There are different types of grow light and each of them have their own advantages and disadvantages. However, to fully understand the use of grow lights, you need to look at its light spectrum. Here’s the graph of the light spectrum. (2)

Explanation of the Graph color diagram:

  • White Light – Directly in the middle between 500 to 600mm. Represents the sun and is known as solar light. This is considered the full spectrum. (3)
  • Blue Light – Triggers the plants to make more leaves. (3)
  • Red Light – Triggers the plants to fruit. (3)
  • Visible Light – This light is what human beings can see. This is known as “PAR” (Photosynthetic Active Radiation). PAR is what your plants will need, and this is the most important section on the light spectrum. (3)

Give your plants the right color of light that they need to optimize their growth and fruit development. Use a grow light that aims for the PAR light spectrum, since you will grow different varieties of plants. Blue and red spectrum lights are suited only for specific plants.

Types of Grow Light

Type of Grow Light Pros Cons

CFL (Compact Fluorescents)

  • Inexpensive
  • Effective for low light plants
  • Needs reflector to be efficient
  • Ideal only for small growing spaces

T5 Fluorescent

  • Cheap
  • Compact
  • Easy to buy locally or online
  • Low electric usage
  • Few heating issues
  • Only useful for plants with low to medium light requirements
  • Bulbs needs to be replaced every 9 months
  • Expensive


  • Less expensive than LED
  • High yielding
  • Bulbs need to be replaced every year.
  • Generate more heat than other fixture


  • Energy efficient.
  • No need to use ballasts, reflectors and cables
  • can be used in tight spaces
  • Operates at a lower temperature
  • Higher initial cost

Compact Fluorescents

In purchasing CFL, look for bulbs that are labeled as “grow light”. CFLs comes in many wattages and plants’ growth is not very good under this light.  CFL should only a supplemental lighting to your indoor aquaponic garden, when you can get at least some sun each day. (1)

No matter what kind of CFL bulb you use, put a reflector behind the bulb, as  CFL shines light in all directions and you need to capture the light that shines away from your plants. Reflective aluminum can be used as a reflector. (1) 

Using CFLs as your grow lights might be a good choice since they don’t need ballasts or special wirings to use but they are not the best light to use in an indoor or greenhouse aquaponics garden. One reason is CFL’s are only economical options when your growing spaces are smaller, if you have larger indoor garden you might need to set up two or more CFL bulbs which can be costly. (1)

Recommended CFL Product

AgroBrite FLC13D Grow Light Bulb, KAEZI 5500K CFL Day Light Bulb SunBlaster CFL Self ballasted Propagation Lamp

T5 Fluorescent

T5 Fluorescents is great for seed starting and lighting rectangular beds up to 4’ in length.  T5s are low heat lights so you can put your bulbs close to your plants, which makes T5s ideal for low ceiling growing spaces. One of the dis-advantage of T% grow lights is you need to replace the bulbs every 9 months and T5s are not inexpensive kind of light.


Recommended Fluorescent Products

Hydroplanet 4ft 8lamp Fluorescent T5 Grow Light Ho Fluorescent Oppolite 4-Lamp Grow Light Kit Fluorescent

HID (High Intensity Discharge Lights)

HID are excellent for growing indoor plants for a relatively low initial cost. HIDs are more efficient than fluorescent lights and a much better choice for larger and more demanding indoor plants. HID light has an awkward shape and is often used in conjunction with a reflector which directs the light downward towards the plants. HID setups are generally configured with interchangeable ballasts, reflectors, and bulbs so you can mix and match the components to fit your style or budget. (1)

Recommended HID Products

VIVOSUN"Butterfly" Double Ended Grow Light Fixture iPower Digital Dimmable Grow Light Apollo Horticulture 315 Watt Grow Light

LED (Light-Emitting Diode)

LED are the best on the market today. The reason for this is that LED manufacturers are getting control over the spectrum of light that are emitting out of LED fixtures by fine-tuning the range of LEDs on the panel.  LED fixtures are more energy efficient compared to other grow lights. (4)

Led grow lights are power saving fixtures as LEDs operate using a lower wattage. In LED, there is no need to use ballast and reflectors or running cables in between since all the electronics are contained within the unit.  LED grow lights can be used in tight spaces and operate at a lower temperature, so you can control your grow room temperature easily. Using LED in your indoor or greenhouse aquaponic garden has many advantages making LED our best choice as the best grow light to use.

Recommended LED Grow Light Product

LUXAUTO LED Grow Light WAKYME Adjustable Full Spectrum Double Switch Plant Light MARS HYDRO TSW 2000W Led Grow Light

What Exactly Should You Use?

High output T5 are bright enough to grow all types of plants. They are safe and cool and do not have a hot single blinding point of light as HID lights. T5 are very safe to use above the plant you’re growing as they have bulb shield and wire guard. T5 is far less expensive than LED, and so our recommended light is the T5 grow lights. (1)

How long should you run your lights?

The answer would depend on the plants you are growing and whether they have access to the natural sunlight.  When you’re in the vegetative space and you don’t have access to sunlight, run your light for fourteen to eighteen hours  a day. If your plants are flowering and fruiting, run your lights for twelve hours in a day if you don’t have access to the sunlight. However, if you have access to sunlight, then the time for you to run your light will differ depending on whether your sunlight is direct or not. It’s advised to do an experiment to figure out the best length of time to run your lights. (5)

How High Can You Hang Your Lights Over Your Plants?

The general rule for the exact hanging of an HID lamp is twelve to forty-eight inches depending on your wattage. LED, induction lights and fluorescent lights produce less heat, so you can place them closer to your plants. Your plants grow in height, so you also need to adjust the height of your light once your plants have grown to avoid too much heat in your plants. (5)



You can feed your plants with the right nutrient balance, have the right temperature and humidity or fill your greenhouse or room with the right amount of air, but without the proper grow lights none of those things really matter as grow lights are one of the most important components in growing plants indoors or in a greenhouse. Thank you for reading our grow lights guide. Join our Facebook community if you want to learn more about aquaponics.