Using LED Grow Lights: 9 Mistakes to Avoid

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LED grow light is an excellent alternative to natural sunlight for plants. However, there are some mistakes you’ll need to avoid to ensure its longevity.

You should prevent inadequate distancing and height settings from the lights. Besides, avoid overheating and overwatering the plants. Make sure you use quality LED grow lights with suitable light spectrums to give sufficient lighting. Also, remember to plan proper light scheduling and maintain your lights on time. Lastly, keep in mind other growth factors to grow healthy indoor plants.

Let’s discover the ten mistakes you should avoid when using LED grow lights to grow your plants!

hydrophonics hothouse with agricultural cultures and led lighting equipment

1. Inappropriate Distancing

We have talked about LED grow lights’ advantages to plants. Yet, it is not that the more, the better. 

Some growers will mistake placing these lights overly close to the plants, thinking it will benefit them more. It will result in overheating, bleaching, causing leaves to turn crisp. Providing the wrong light spectrum will also cause stressed growth. 

Some other botanists are too used to HID grow lights and mistakenly place the LED grow lights too high. As a result, your plants will overstretch and end up with weak growths. 

Actually, how close should we put the lights to the plants? 

In fact, there are no standards defined for the best distance between your plants and the grow lights. It depends on several factors, like the type of plants, growth stages, amount of ambient light, type of LED plant grow lights, etc. 

You can refer to the suppliers’ website or product user manual to find out more. If unsure, place the LED grow lights 12 to 18 inches from the top of the plants. 

The suggested distances are 24-36 inches during the vegetation phase. Place the lights nearer during the flowering stage at about 12-24 inches higher. You can also refer below for different plant types:

  • 4 – 6 inches for seedlings
  • 6 – 12 inches for hydroponic plants and herbs
  • 6 – 12 inches for flowering houseplants
  • 12 – 24 inches for foliage houseplants

Make sure you provide a well spread of lights to your plants for better and healthier growth. You must also adjust the heights of LED grow lights accordingly when your plants grow taller. 

It is crucial that you spend some time monitoring the condition. If your plants grow well, consider moving the lights closer bit by bit. Don’t forget to rotate your pots and adjust the height of lights when needed. 

greenhouse plant row grow with led light indoor farm agriculture technology

2. Overheating the Plants

You should also be cautious not to overheat your plants. Though LEDs produce lesser heat than other technologies like HIDs, they can still make a high light level. LED grow lights might damage your plants if you do not pay close attention to them. Note that a PPFD of 800 is harmful to your plants.

In this case, you should be careful of oddities. For instance, browning, bleaching, drying, and curling leaves are overheating signals. You should lift the LED grow lights higher to prevent burnings of leaves and buds. 

It is also crucial to ensure adequate airflow in your gardening space. A good ventilation system controls the airflow and temperature of plants. It ensures your plant’s safety and allows them to grow at optimal peak.

3. Overwatering the Plants 

What does watering have to do with LED plant lights? 

It turns out that some horticulturists use LED grow lights like how they use HID lights. HID grow lights produce more heat, thus needing extra watering for the plants. However, this is not the case for LED plant lights.

LED grow lights for indoor plants emit much lesser heat than HID lights. Thus, the plant vaporizes up to 50% lesser compared to HIDs. You’ll need to adopt new watering schedules for your plants to prevent overwatering them. Otherwise, there will be pests, plant diseases, rotten roots, etc. A good practice is to water only when the soil is nearly dried out.

In addition, a quality LED grow light will enhance the photosynthesis efficiency of plants by converting more carbon dioxide to glucose. As a result, you can reduce the watering and even fertilizing to save you more fertilization costs. 

Choosing an optimum growth medium is crucial for your indoor plants. It can provide better drainage and water protection, as well as nutrients required by the plants. In contrast, a poor medium may cause nutrient loss or deterioration. 

Remember to pay attention to the pH value of water use. In general, a pH value of 5.5 – 6.5 is the most suitable for plant growth. 

greenhouse vegetables plant row grow with led light indoor farm technology

4. Using the Wrong Light Spectrum

Sunlight is an essential element for plants to carry out photosynthesis. Thanks to the advancement of technologies, LED grow lights have been invented to provide a sun-like spectrum for indoor plants. But, do you know that plants require a specific light spectrum for different growth stages?

To ensure healthy plant growth, you should use the correct blue, red, and white lights. For instance:

  • Blue light encourages sprouting and strong rootings during the germination stage. It is also for the leafy greens and non-flowering house plants.
  • Red light is good for the flowering and blooming stage to promote budding for flowering plants. It also retains the short height of plants.
  • White light is for almost all types of plants at any growth stage. 

The best solution is to buy full-spectrum LED grow lights useful for vegging and flowering. These lights have a switchable spectrum according to the growth stage of your plants.

It will provide a sufficient spectrum for all types of plants. 

Remember to do the proper settings based on your plant types and the seasons. 

5. Using Inferior LED Grow Lights

LED grow lights can make or break your indoor gardening, depending on the quality you use. You should learn the consequences before you buy cheap LED grow lights.

Lower prices often mean lower quality. While it might be tempting to buy cheap LED grow lights, you must know that some suppliers tend to overpromise when selling their products. The fact is that their grow lights might not emit as much light and could not grow as many plants as they guaranteed.

Besides, inferior LED lights are mostly manufactured without adopting safety standards. It will lead to several safety issues like fire hazards. What’s more, some come with a poor cooling system or over-powered lights. You’ll find a significant reduction in light intensity under regular use in just a few months! 

Obviously, it will only waste your time, money, and efforts, in the long run, to repair or replace them. Your plantation plans and schedules could also be affected, hindering plant growth.

That is why you should avoid cheap and low-quality LED lights when buying LED grow lights from China. It is crucial to survey the market and inspect the products before purchasing LED grow lights. Also, buying LED grow lights with certifications like UL certificates or inspection reports like SGS inspected will ensure the quality of the light.

If you are still confused about choosing a suitable LED grow light, you can refer to this article.

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6. Inadequate Lighting

You must also avoid the mistake of providing too little lights to your plants than they need. In fact, many beginners in horticulture get mystified by the specs and numbers told by the suppliers.

Some suppliers will tell that about the high wattage of their LED grow lights for indoor plants. Yet, the number that tells about the number of lights that LED emits is not wattage. Wattage tells about the energy required to produce light, not the actual light intensity. And yes, high voltages lights might still give a poor performance!

Lack of light will hold chlorophyll production, causing yellowish leaves and even dropping leaves. The stems will overstretch to reach the lights, and the plants might not produce flower buds.  

Some of the standard measurements used to measure lights are as below:

  • PPFD (Photosynthetic Photon Flux Density) tells about the amount of usable light that the plant leaf’s surface receives.
  • Lumens measure the brightness of light towards the human eyes but are less relevant to measuring plants.
  • Foot-candle is the quantity of light reaching the 1-square-foot surface placed a foot away from the light. Yet, it is rarely used.

If you’re not sure, check with your manufacturers and read the reviews online before you buy full-spectrum LED lights. 

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7. Bad Light Scheduling

Do you know the proper light schedule needed by your plants? Some gardeners mistake providing the wrong light scheduling for their plants. The truth is that having the best LED grow lights is not enough if you provide bad scheduling for your indoor plants. 

Improper light cycles and spectrums will affect the healthy growth of your plants. Needless to say, forgetting to switch off the light will cause the burning of plants. What about forgetting to switch on the LED grow lights for indoor plants? Your plants will not get enough sunlight to photosynthesize, so of course, they will not grow fast!

Light duration or photoperiod is the duration of light the indoor plants require per 24-hour period.

  • Short-day indoor plants like chrysanthemum only need a short time to flower.
  • Long-day plants like African violets will bloom if you provide daylight more than the night hours. 
  • Day-neutral plants like Crossandra are less sensitive to day length to bloom.

After knowing the type of photoperiod, you also need to know your plants’ total light hours required. It is a good idea to use timer settings to provide your indoor plants with the sufficient lights they need. 

  • Seedlings need 16 – 18 hours of light daily.
  • Hydroponic plants and herbs need 12 – 14 hours of light daily.
  • Foliage houseplants need 12 – 14 hours of light daily.
  • Flowering houseplants need 14 – 16 hours of light daily.

You’ll need to consider a few criteria to decide the number of lights required by your plants. For instance, indoor environment, the surface area of the growing space, type of plants, amount of plants to grow, type of LED plant grow lights, etc.

plant sapling cannabis growing in pot with led grow light

8. Lack of Maintenance 

Having the best LED grow lights don’t mean happily ever after. Note that you need to make frequent maintenance to ensure a good return on investment – the capital you spent for it. You can also save more costs, time, and effort by keeping them in good condition.

In this case, you should use power stabilizers to equalize the light voltage of lights. It will protect the chips inside, giving the LED grow lights a longer lifespan and better performance. Besides, make sure you use the LED plant lights for plants only and not for any other use. Otherwise, it will damage faster than you think. 

You should always prepare adequate spare part supplies for maintenance purposes. Whenever you perform the maintenance, check for coiled cords that will cause under-performing or light failure. 

In addition, inspect the light, base, and socket and look for discolouration, bluing of metal, or black carbon buildup that can cause ballast failures. You need to clean the dirt build up too. 

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9. Neglecting Other Growing Factors 

Light is vital for plant growth, but it is not the only factor needed. You need to take care of other essential things when growing indoor plants. They are water, nutrients, air, temperature, room to grow, and time.

Make sure you give sufficient water to your plants, which we’ve mentioned above. Besides, nutrients are mostly dissolved in water, which is why you need not apply fertilizers too much and too often. The vital nutrients for plants are nitrogen, potassium, and phosphorus. 

You should also pay attention to the temperature. When the temperature decreases in winter, the seeds and seedlings might not grow or even germinate. That is why you need to adjust the temperature accordingly.

Remember to allow good ventilation, so your plants can get enough carbon dioxide. In addition, you should check the original place of the plants to know the best temperature for them. 

Don’t forget to give sufficient room for leaves to grow and for roots to expand. Last but not least, you should know that your indoor plants need some time to grow, flower, and fruit. Check for their plant type to see the time required, so you don’t get too impatient waiting for it.

green salad plant under led grow light. 3d illustration

Final Thoughts 

To conclude, buying a full-spectrum LED grow light is essential, but you should make good use of them. I hope this article helps share the mistakes to avoid when using LED grow lights.

Need more information regarding LED plant grow lights? Darkless LED is the name you can trust. We have over 20 years of LED experience providing certified and customized LED designs for you. Talk to us to get the best LED grow lights for your plants!

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