What Are Indoor Grow Lights For Plants?
If you’re brand new to indoor growing, you may not be aware that indoor grow lights for plants are such an instrumental part of the garden.
Think about it like this - when you’re growing outdoors, you have the sun to provide light energy to your plants, helping them grow and meet their full potential.
But when you grow indoors, you need to replace that light source artificially - which is where indoor grow lights come in.
These allow you to grow your plants anywhere in your home - whether it be your garage, a shed, a closet, a spare bedroom - you name it. You can harness the power of the sun and take it indoors to grow your favorite plants, year round.
What Are The Different Types Of Plant Growing Lights?
These days, there are lots of different plant growing lights - not just the incandescent ones you may be used to. Nowadays, there are 4 main types of plant growing lights you should know about:
- CMH’s (LEC)
- HID’s (MH & HPS)
- Fluorescents (CFL & T5)
Now, which one of these plant growing lights is right for you and your grow room or grow tent? That depends entirely on your budget, your goals, and the type of plant you are cultivating. We’ll break down the pro’s and con’s of each lighting technology below to help you understand which is right for you.
What type of grow light is best for growing plants indoors?
There are many different types of grow lights for indoor plants, each having its place in indoor growing. The best option for YOU will depend on your growing space and your budget.
Fluorescent grow light fixtures for plants
Fluorescents are often used by beginners due to their low price, low heat output, and the familiarity that comes with them. Compact fluorescent grow lights (CFL) fall under this category along with fluorescent T5’s, which are popular with growers on a budget or who only want to grow 1-2 plants at a time. Most of our fluorescent options run on 120 volts and can be plugged into a standard home outlet.
- Very affordable startup cost
- Low heat output
- Great for growers whose grow space is short on height – these lights need to be very close to plants
- Not as intense as other options
MH and HPS grow light fixtures for plants
HID grow lights have been the golden standard in horticulture for decades, with a high watt to lumen ratio and ideal light spectrum. They do, however, require three crucial components (bulb, ballast, and reflector) to work which adds to both the initial cost and complexity.
There are two main types of HID lights: Metal Halide (MH) and High Pressure Sodium (HPS). MH’s bluish light is great for the vegetative period, while HPS’ reddish-yellow light offers a near perfect light spectrum for flowering.
Ballasts can be plugged into a standard 120V or 240V outlet. Without a reflector, HID lights have too large of a light footprint and need to be reduced. Reflective hoods redirected wasted light back towards the plants. Different size reflectors allow you to customize your light footprint.
- High intensity light
- Relatively inexpensive despite multiple components – can be purchased as a kit
- Dimmable ballasts allow you to change wattage giving you control over footprint, power usage, and reduces the strain young plants may feel with higher wattage
- These bulbs need a special hood and ballast before they can be plugged into a regular light socket
- High heat output – will need to be removed from the room
- High height requirement – depending on wattage these lights will need to be around 1-2 feet away from plants
- Bulbs will need to be replaced every 1-2 years, but they are inexpensive
Double ended (DE) grow lights improve on the quality and quantity of light compared to single ended (SE) grow lights. Double Ended HID lights commonly offer growers a 10-30% increase in both light intensity and PAR output. DE globes are also more durable and last longer than traditional SE (single ended) globes.
We recently wrote a guide on the best HPS grow lights currently on the market. If this technology interests you, check it out and make your shopping experience easy as possible!
Ceramic Metal Halide (CMH) Grow Light fixtures for plants
Ceramic Metal Halide (CMH) or Light Emitting Ceramics (LEC) operate similar to HID lights, but instead of using quartz it uses a ceramic arc tube. Many CMH lights are “plug-and-play” which means they have a ballast and reflector included, and can usually be plugged right into a standard house outlet (120V) or a 240V outlet. Read our review of The Best CMH Lights Of The Year if you want some specific recommendations. Otherwise, here are the pros and cons of this technology:
- High lumen and Par output
- Low heat output and energy efficient
- Bulbs last longer and keep their brightness longer than traditional HIDs
- Offer a natural light spectrum i.e when the lights are on they don’t “color” your plants purple like LED lights or yellow like HPS, and this make spotting plant issues very easy
- Smaller light footprint than their HID counterparts
- They are more expensive.
LED grow lights fixtures for plants
LED grow lights are where the horticulture industry is headed, and many of the best growers around the world have already upgraded their facilities to use these exclusively. They have been rapidly coming down in price and are usually sold as a complete unit – meaning you can plug most of them straight into a regular 120V home outlet.
Soon, they will rival HID lights in commercial growing operations, and many home growers are already switching over. LEDs have a much smaller light footprint compared to HID lights and do not require a reflector.
- Extremely low heat output
- High intensity light with some models having adjustable spectrums for veg and bloom.
- Very affordable in the long run – the lights have an incredibly long lifespan and they are extremely energy efficient
- High initial cost
- Lots of confusion regarding the best light spectrum and diode color ratio.
- High height requirement – Often these lights need to be at least 24” away from plants
Frequently Asked Questions About Indoor Grow Lights For Plants
For those new to indoor growing, we’ve compiled the top questions we get pertaining to indoor grow lights fixtures for plants.
If you still have questions after browsing these, feel free to reach out to our expert growers and we’ll help provide some clarity, and get you exactly what you need!
How many hours a day should you use a grow light for indoor plants?
During vegetative growth, also known as vegging, plants need lots of light. Give plants at least 18 hours of light, followed by a 6 hour dark period so the plants can rest. Some growers report higher vegetative growth rates from a 24 hour light cycle. Experiment with both, and if you don't want to be using electricity 24 hours a day, 18 hours is plenty.
During flowering, reduce the photoperiod to 12 hours of light followed by 12 hours of darkness. This simulates the shortening of days, and encourages plants to begin producing big, heavy buds.
Should I Turn Off The Indoor Grow Light At Night?
Many growers wonder whether they need to turn off their indoor grow light before bed each night. This is a complicated question, because it depends on what type of plant you’re growing.
Different plants have different lighting needs. Some need just 6-8 hours of light a day, whereas others can benefit from 24 hours of light exposure per day!
So first, determine your specific plant’s lighting needs. Then, ask yourself, do you really want to have to ever worry about turning off your lights? The answer is likely no, as this forces you to be home each and every night to turn your plant grow lights off at the right time. This just isn’t feasible.
Instead, simply grab a timer or controller and connect it to your fixture. You can automate this process, so your light turns on and off without you having to do anything!
Can regular light bulbs grow plants?
While you may be able to grow plants with shop lights or some fluorescent house lights, the quality of the plant will suffer. For one, these lights do not contain the full spectrum grow lights for indoor plants do. Plants need blue and red light for optimal growth.
What are the best hydroponic lights?
Hydroponic systems can operate using the same lights that soil plants do. Hydroponics simply refers to the system used to grow the plant, such as DWC, Ebb and flow, etc. If you want to switch from growing in pots and soil to a hydroponic system, you can keep using the same light system.
Are grow lights bad for your eyes?
Prolonged exposure to certain full spectrum grow lights for indoor plants can have detrimental effects on your eyes. It should go without saying that you should never look into any type of light, as these are designed to be intense. LED’s and HID’s are especially intense, and if you plan to work around your fixture for an extended period of time, you should use grow room glasses and eyewear.
Should I Consider a Grow Light Mover?
If you would like to make sure your plants are getting as much light as possible, and you want to make the process as simple on yourself as possible, a plant grow light mover can be a great addition to your system. These will have a rail and a motor system where you can hang the lights, and then the lights will automatically move back and forth to provide your plants with the ideal amount of light coverage. They are an added expense, but many believe them to be well worth the cost.
What Color Is Best for Vegetative and Flowering Stages With Plant Grow Lights?
Different colors on the light spectrum are important for different stages of a plant’s life. While you can find full spectrum lights that are capable of providing everything a plant needs, you will find that some types of lights, such as HID lights, have specialties. The metal halide lights that fall into this category, for example, produce a blue light. This is good for plants when they are in their vegetative state. The HPS lights emit a reddish light, which is better for the plants when they are in a flowering state.
What Is the Color Rendering Index Of Plant Grow Lights For Indoor Plants?
The color rating index is a measurement of just how accurately a light source can illuminate the true colors of an item. Having a high CRI rating means that you know exactly what color the lights you choose are emitting.
Can a Plant Grow Light Reflector Really Help?
You want to make the most out of the light emitted by your bulbs, naturally. Much of that light is lost if you are not using a quality full spectrum grow lights reflector. They can help to make your setup far more efficient, and they are highly recommended.
What Wattage Plant Grow Lights Should Be Used?
The “best” wattage will depend on the type of plants you are growing, along with the amount of space you have for the grow room. However, there are some simple rules of thumb that you can remember. For a 2’x2’ space, you will need 250W. A 4’x4’ space will need between 400W and 600W. A larger 8’x8’ space will need to have about 1,000W. Again, be sure you understand what the particular types of plants you are growing need to thrive.
Here at Hydrobuilder, we have the best selection of plant grow lights for sale. Buy grow lights for indoor plants here and get the same technology the pro’s use, for less!
Plug, you get to enjoy our industry leading customer service that has hobbyist and commercial growers alike coming back for more, time and time again. And we don’t just carry lighting fixtures - we are a complete garden superstore, carrying everything from grow tent kits to nutrients to harvest supplies, and everything in between.
For more information on Indoor grow light fixtures for plants, visit our learning center, where we have an entire section on them! If you have any questions, call our experienced growing staff at 888-815-9763!