Indoor Growing, Led Lights

Indoor Grow Lights Beginner’s Guide: Everything You Need to Know

Are you planning on growing vegetables at home? Setting up a hydroponic or organic garden indoors is a great way to grow fresh veggies to feed your family this year.

Growing indoors means that you don’t have to concern yourself with changing weather conditions. Not to mention, the chances of pests and disease attacking your plants is much lower than in an outdoor garden.

However, growing indoors means that you’ll need to simulate the growing environment using technology. The most challenging part about growing indoors is finding the right grow light for your garden. There are plenty of benefits and uses for indoor grow light systems.

  • Grow your plants from seedling to harvest, without any sunlight
  • Start seedlings early before transplanting to the garden in early spring
  • Use specialized lighting systems for propagating and flowering
  • Finish outdoor plants that don’t have enough light left in the season
  • Propagate your plants and your root cuttings
  • Grow plants inside all year-round

These are a few examples of the benefits of using a grow light and indoor growing system for your vegetables this year. So, what is the best indoor grow lamp for your garden?

This post will investigate everything you need to know about selecting the best growing light system for your indoor growing needs.

Grow Lights – Vital Concepts

Before you settle on a grow light for your indoor garden, we need to go over a few concepts regarding how light affects plants and growth. Understanding these basic concepts will give you everything you need to choose the right lighting system.

The Light Spectrum

All light waves, both visible and invisible, fall somewhere on the spectrum. Science measures these wavelengths in nanometers, corresponding to the specific wavelength on the spectrum.

The light we’re interested in using for our indoor growing falls on the 400nm to 700nm spectrum. Light waves of this intensity are also known as Photosynthetically Active Radiation (PAR). PAR refers to specific wavelengths that plants use for photosynthesis processes to inspire growth.

Within this PAR bandwidth, there are wavelengths plants use for specific biological functions.

  • 400nm to 490nm – This wavelength produces blue light used by your plants during the vegetative state as they grow.
  • 580nm to 700nm – This “orange-red” wavelength mimics the sunlight in the later summer and early fall, signaling your plants to start fruiting.

For those that are math geniuses, you’re probably wondering why we skipped over the light waves in the 490nm to 580nm range. The chloroplasts in plant cells reflect light at these wavelengths since its mostly green in the 510nm to 570nm range.

Light Intensity

Now you understand PAR and the types of light required to boost growth and flowering in your plants. The next step is to understand how much of that light we need to use to grow healthy plants and increase harvest yield.

The amount of light produced by the light source reaching your plants refers to its “intensity.” The type of light plays a significant role in the intensity of the light waves. The positioning of your light also plays a vital role. The closer it is to the canopy, the shorter the distance to the light, and the more intense the light waves.

Therefore, the proper positioning of your grow light is critical. Too close to the canopy results in the burning of your crops. Having the light too far away from the canopy means that the plants don’t get the light they need for optimal photosynthesis.

Grow Light Power Consumption

Your grow light draws electricity to operate the ballast and bulb. Grow lights can vary in wattage, from as little as 50-watt NIR bulbs to 2,000-watt HPS or LED setups. Some growers use multiple lights in series, boosting the power capacity of their setup to meet the harvest needs.

Some lights have higher wattages than others. For example, LED lights have lower wattages than HPS or metal halide bulbs. Therefore, these light sources consume more power than LEDs, cutting down on the costs of operating your indoor garden.

Each growing light has a specific design to cover a growing area. Trying to grow outside of this light footprint will produce lackluster results. The wattage of the bulb, and it’s operating height are the two most significant factors to consider when deciding on the right light footprint for your garden.

For example, a 1,000-watt globe operates at three to six feet above the canopy, and it’s suitable for a growing footprint of up to 3-square feet. When setting up your grow light, we recommend you follow the manufacturer’s guidelines for distance from the bulb to the canopy.

You can tweak these settings with small tests during your first harvest. It might take you the entire growing season to find the right setup for your garden. Finding the proper placement to provide optimal heat, intensity, and footprint takes some time and testing.

Plant Photoperiods

The photoperiod of your light refers to how much light you give your plants over 24-hours. If you’re growing outdoors, you have a limitation on the photoperiod, thanks to the sun. In the height of summer, you can get up to 12-hours of light each day, while the wintertime may shorten daylight to 6-hours.

When growing plants indoors, you can change the photoperiod to whatever length you desire. You can run a 24-hour photoperiod with consistent lighting if you want.

Some plants experience a change when they start to experience a shortening in the photoperiod window. This shortening of the photoperiod mimics the days of the harvest season, and the plants begin to flower.

What are the Types of Indoor Grow Lights?

Now that you understand the basics of indoor lighting, it’s time to discuss the types of grow lights available. This topic is confusing for many indoor gardening newbies. Understanding the difference between the lights helps you choose the right light to match your needs.


Fluorescent bulbs are a popular choice for starter gardens. The blue-white spectrum of the light is ideal for starting seedlings and growing young plants. Best of all, these fluorescent globes are cheap to run, using hardly any electricity.

CFL bulbs are an excellent choice for vegetative gardens, and there’s no chance of this light spectrum burning your plants. You can leave the bulbs within a few inches of the top of the canopy, and the tips of your young plants won’t burn.

The CFL bulbs don’t put out much heat, and if the leaves of your plants touch the lamps, it won’t result in a burn. Both commercial and hobbyist farmers use fluorescents to start plants before moving them into the flowering phase.

Some plants, such as leafy greens like spinach and kale will do well under these lights, and they don’t require any transition to another light source for additional growth. T5 bulbs are the most popular type of CFL bulb available.

You’ll need several of these lights over one growing area, and we recommend packing in as many as you can fit.

Light Emitting Diode (LED)

LED grow lights are the new gold-standard in indoor growing. These lights were the next evolution from the high-pressure sodium and metal halide globes. However, LED costs a fraction of the price to operate when compared to HPS and MH globes. LEDs produce less heat and consume less electricity.

The early stages of LED technology were skeptical, and many growers were hesitant to use them due to the technology’s unproven nature. However, over the last 10-years, LED technology has made remarkable progress, and todays LED lighting systems are as effective as HPS or MH, without the sizable energy bill.

Some LED models also feature dual-spectrum output. You can start your plants on a vegetative light spectrum, and they turn them to flowering with the click of a switch. These lights are typically more expensive, but the dual operation comes in handy.

Metal Halide (MH)

MH lighting is a favorite choice for indoor gardeners during the vegetative phase. This light produces the growing spectrum, providing plenty of power and intensity to supercharge the growing period.

However, these lights consume plenty of power, making them an inferior choice to CFL in terms of value for money. MH produces the blue light plants that need to grow, and they are suitable for wattages up to 2,000-W

High-Pressure Sodium (HPS)

The HPS bulb produces light in the red range between 600nm to 700nm. This spectrum mimics the waning days of summer and spring, and the daylight hours start to get smaller. If you’re growing vegetables that rely on changes to photoperiods to flower, turning on your HPS bulb after the vegetation cycle will induce flowering.

These lights push out plenty of heat, and you’ll need an external ballast you can set up outside the growing area to keep the temperature down. HPS is an intense light and comes in power ranges from 400-watts to 2,000-watts.

These bulbs are notoriously expensive to run. Many growers decided to leave their HPS systems in favor of LEDs in recent years.

Ceramic Metal Halide (CMH)

These globes offer indoor growers the best of HPS, and MH roiled into one platform. These lights have a balanced spectral output, providing a mixture of red, orange, and blue light. As a result, you can grow with one bulb year-round without the need to switch to different spectrums.


Plasma bulbs are the new evolution of LED. These systems are gaining traction with growers due to the efficiency claims around the power consumption of these models. They offer the same one-size-fits-all growing spectrum, but they are considerably more expensive to purchase than most LED systems.

Cooling and Heating Effects

One of the byproducts of running indoor growing lights – is heat. CFL bulbs and LEDs put out very little heat during operation. As a result, you’re not going to notice any changes in your indoor growing temperatures.

However, MH and HPS bulbs do produce significant amounts of heat. As a result of the light intensity produced by these bulbs, you might notice that the temperature inside your growing room may increase by up to 12-degrees. The increase depends on the size of the lamp and your growing conditions.

To mitigate this effect, you’ll have to install fans or an air-conditioner to lower the heat back to reasonable growing temperatures.

How Do You Maintain Your Grow Lights?

There are a few basic principles you can follow to maintain your lights. In most cases, the ballasts will only require some minor cleaning, and you might have to open the ballast once a year to blow out the dust.

Watch Out for Bulb Light Degradation

All grow bulbs will start to lose efficiency and power over time. A degraded bulb doesn’t produce the necessary amount of light to create the best crop effects. As a result, you’ll need to swap out bulbs at least once a season to prevent degradation.

However, different types of bulbs provide different service life, depending on the type, wattage, manufacturer, and use in the garden.

T5 Fluorescent Bulb Degradation

Fluorescent light degrades the slowest out of all the options you have. These bulbs will lose around 10% of lumen capacity for every 20,000-hours of working time.

LED Bulb Degradation

LEDs degrade the slowest. For example, an incandescent bulb using filament, lasts for around 6 to 9-months, depending on your frequency of use. In contrast, a LED will last you between 15 and 20-years.

Most manufacturers will rate LED systems at 50,000 to 100,000-hours of operation before the diodes require replacement.

When Do I Replace My Bulbs?

You’ll have to replace your bulbs sooner or later, and we recommend sooner than later. Replace MH and HPS bulbs after they reach 50% degradation – we recommend after each harvest season, or every 8 to 10-months.

Indoor Grow Light FAQs

Do you have a few more questions about using indoor grow lights? Check out this FAQ for the answers you need.

How much light do indoor plants need to thrive?

Some plants are different than others. We recommend you run your lights for 16 to 20-hours on vegetative crops. You can use an MH or CFL bulb for this purpose. If you’re flowering vegetables or fruits, you’ll need to drop the photoperiod to 12-hours on, and 12-hours off.

Try to avoid running your lights for 24-hours; plants need time to rest and recover – just like you. We recommend you buy a timer and link it to your lighting system. You can use the controller to nominate your lighting hours, without the need for manual intervention.

How close can fluorescent bulbs come to my plants?

CFL bulbs won’t damage your plants. Even if the foliage ends up sitting on the lamp directly, you shouldn’t notice any burning or damage to the leaves or flowers of your plants. However, we recommend that you always keep the lights around 2 to 3-inches away from the top of the canopy.

Don’t move them any higher than that, or you’ll start to experience a slowdown in your plants’ growth. As mentioned, change your CFL bulbs at least once a year to avoid bulb degradation and keep your garden thriving.

How often must I replace HID lighting like HPS and MH bulbs?

It depends on how often you use the light and the duration of the photoperiod you’re trying to emulate. As a good rule of thumb, we recommend replacing MH and HPS bulbs after each season for the best results.

HPS and MH bulbs are expensive, so you’ll need to account for the costs of the bulbs in your gardening budget. Ceramic metal halide bulbs last a bit longer than the other HPS and MH variants. You might get away with two growing seasons before you notice severe bulb degradation occurring.

Is growing under LEDs worth it?

Many indoor gardeners swear by LED systems, while others steer clear of this tech. When selecting your LED grow light, make sure you look at the PAR, lumens, and the wattage of the light before finalizing your purchase.

Follow the directions and guidelines for growing under these lights, placing the light too close to the canopy results in the burning of the plants. For seedlings and sprouts, we recommend you keep the light at least 24″ to 28″ above the canopy. You can drop the lights to 18-24″ overhead during the transition phase, and 12″ to 18″ during the flowering cycle.

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