How to choose the best led grow lights? - 12 years LED manufacturers tell you the truth
Recently, when people choose LED grow lights, they have an increasing preference to buy multi-bar style lights. Multi-bar style LED grow lights have uniform PPFD distribution, supreme heat dissipation, and can be applied to any kind of growing scenario. As a result, it has apparently become the new grow trend.
With so many multi-bar LED Grow Lights on the market, it can be challenging to find the right one. With so many models out there and vague technical specifications, a simple search turns into hours of research.
On top of all that, many multi-bar LED grow lights you find online are not telling the whole truth about their product. Many retailers are dishonest about what their LED grow lights are actually capable of.
Luckily, there are reliable and efficient multi-bar LED grow lights on the market, but you need to know how to find them. That's why we're going to show you how.
Continue reading below to find out useful tips for choosing the best multi-bar style LED grow light that will give you your best crop yet.
1. Focus on the LED chip - brand and model
2. Look at chip quantity - low current driving chip
3. Uniformity of PPFD
4. Check Running cost and Yield per watt
5. Get the real deal
Focus On the LED Chip
When most people search for an LED grow light, they focus on the shape of the grow light. However, the LED chip itself is much more important than a grow light's shape.
The LED chip is the source of the light, so having high-quality LED chips is a must.
The easiest way to tell a premium LED chip from a lower-quality one is by brand. The better the chip brand, the better the build quality, efficiency, light output, and reliability.
However, Samsung isn't the only good LED chip manufacturer. Other excellent LED chip makers are Osram, Bridgelux, and Epistar...
More budget-oriented grow lights can still give an incredible performance without using Samsung LED chips.
LED Chip Model
One thing you need to pay attention to isn’t just the LED chip’s brand, but the model, too. That’s because the model of the chip can play a big role in how well the grow light will perform.
For example, Samsung’s 3030(LM301) LED chips line includes models called LM301H, LM301B, and LM301D. Both LM301H and LM301B are the true top-of-the-line LED chips while LM301D doesn’t offer the same amount of energy. Other less efficient and not suitable for planting Samsung 2835 (LM281) series LED chips will not be discussed here. Of course, when you buy, you need to pay attention to choose the most suitable series for growing - Samsung 3030 (LM301) series lamp beads
We can see this easier when we compare their specs:
- LM301H - 230lm/w (3.1 μmol/J)
- LM301B - 220lm/w (2.92 μmol/J)
- LM301D - 211lm/w (2.7 μmol/J)
Make sure you dig a little deeper and see that an LED grow light has the best chip model.
One thing you need to be aware of is that there are many fake LED chips on the market. Some LED grow lights claim that their product uses Samsung LED chips, but that couldn't be further from the truth.
LED chips make up over 70% of the light building cost, and when it comes to Samsung LED chips, the cost will be more than 80%. Many low-cost LED grow lights claim to use Samsung LM301B chips, but there’s one easy trick to see if that’s true. The trick is by looking at cost because a real LM301B chip will cost $0.2 to $0.4 per chip.
If you do a quick calculation, 80% of the whole light cost divided by the quantity of the light chips - the price of the LED grow light seems too good to be true, then it probably is a fake.
To make you understand more clearly, let's set an example here.
One multi-bar LED grow light claims to have 2,500 Samsung LM301B chips, and it sells at US$499.99.
(499.99 x 0.8)/2500 = 0.16 < 0.2-0.4 easy to see it's fake
To make sure you're getting the real deal, you'll need to look at Samsung's official partners. For example, Mars Hydro is partnered with Samsung (click to Samsung’s Partner Announcement), so you can rest assured that their Samsung LED chips are the real deal.
Look at Chip Quantity
When searching for a multi-bar style LED grow light, it's tempting to get one with many bars. After all, the more the bars, the better the deal, right?
Not necessarily, because the vendors don't tell the whole story. That's because the LED grow light with more bars doesn't mean it uses more LED chips. And a high-wattage LED light with few chips may lead it to be inefficient and self-destructive
To understand the whole story better, we need to know a bit about physics. More specifically, we need to know about how a lower current in an LED grow light leads to less heat.
Heating in a conductor--like an LED--is through joule heating, which has the formula I2R. Heating happens when a moving charge (electrons) collides with molecules in a conductor, transferring kinetic energy.
Basically, the lower the current (I), then the internal heat will be much lower.
We need to remember that current is the amount of charge passing a particular area per unit of time. The higher the current, the more charge flowing through, leading to more collisions and more heat.
We know that it can be a little confusing, so we’ll use a real-world example to make the point clear.
The current of each chip of grow lights on the market now is generally above 200mA, which is already overdriven. Low current grow lights, such as Mars Hydro FC6500, have a current of 80mA per chip.
(200)2/(80)2 = 6.25
A high current grow light has 6.25 times more heat per chip than a low current grow light. Please be noted we’re talking about the heat of every single chip because the internal heat of each chip is what really acts. Generally speaking, LED grow lights driven by high currents of 200 mA and above are overused.
Why Lower Current Is Better
Now you might be wondering, why is heat bad?
Heat is bad for LEDs because they reduce the lifespan of the LED chips and lead to light decay.
Most 200 mA driven LED grow lights experience a decrease in efficiency and far less effective grow results after a year of use. This is because the high internal heat causes the chip to become less efficient, the quality of the spectrum deteriorates, and light decay occurs. At this point, even though your plant light is still bright, its performance will be greatly influenced. If you still want to maintain high-quality output, you will have to get a new plant light.
In contrast, a low current (around 80 mA) driven plant light will last for 3 years due to the low internal heat. That's a very big saving!
Now you might have another question: What does it have to do with the number of LED chip quantities?
It’s simple. With a low current drive, the wattage per chip is lower. And to build a whole lamp with over 600W consumption, it will need more than 2000 LED chips.
By the way, many LED grow lights’ vendors refuse to tell customers the number of chips and only announce their wattage and bar numbers, so be careful of this trap.
When you choose between two same-wattage LED grow lights, don’t just go straight to the one with more bars, look at its chip quantity and make your decision carefully. Every penny counts.
A lot of LED grow light companies try to sell you on their product’s lumen output. What if we told you that lumens are not a good way to measure the light output from an LED grow light?
That's because it isn't and the better way to measure LED grow light output is through PPF and PPFD.
The reason lumens aren't a good measurement is because they're purely a human light measurement. It may be obvious, but LED grow lights aren't made for humans but for plants.
To measure light meant for plants, we need to calculate the amount of photosynthetically active radiation (PAR) molecules hitting a particular area per second. That calculation is called photosynthetic photon flux (PPF), which gives us a calculation in μmol/s. [P.S. Photosynthetic Photon Efficacy(PPE) can give you a quick image of the whole light's efficiency, 2.7 μmol/j PPE means a highly efficient LED grow light. The numbers are relevant: PPE x Wattage = PPFD approximately]
If we take it one step further, we can get the PPF density (PPFD). The PPFD measures the amount of PPF hitting an area in square meters (m2).
That means that it estimates the amount of light plants can receive in an area, which is extremely useful for growers. Here’s a list of estimated PPFD values for home cannabis growers:
- Vegetative stage: 400-600 μmol/s/m2
- Flower stage: 600-900 μmol/s/m2
Commercial growers need a bit more juice, and the range of PPFD values are:
- Vegetative stage: 800-1000 μmol/s/m2
- Flower stage: 1000-1200 μmol/s/m2
Anything over 900 μmol/s/m2 and your cannabis will need the help of added CO2.
So what does all this have to do with uniformity? The reason is that many LED grow lights have an uneven PPFD.
You need to avoid LED grow lights with a high PPF in the middle and a low PPF on the edges. That means that the light coming down from the grow light isn't evenly spreading out over the canopy.
So you'll have only the center of your grow area getting good light while the rest of the room gets little. That means that most of the energy of the light only goes towards the middle, leading to wasted energy and hotspots.
These LED grow lights were made with PPFD uniformity in mind. The more uniform the light covers your canopy, the better yields you'll get.
Now we need to really get into the technical nitty-gritty. One of the best ways to choose an LED grow light is by looking at each system's cost, how much it takes to run, and what kind of yield you get from each.
To do that, we need to see how much it costs to purchase a system, how much it costs to run it, and how many grams you can get from it.
After LED grow lights have replaced most HPS lights, many growers still pick lights based on wattage. Now we hope growers will move their eyes from comparing wattage to comparing PPFD values.
Because PPFD values are the real value that measures the amount of light that plants absorb rather than wattage.
For example, let's look at Mars Hydro's 8-bar 650W LED. It’s a 650W system. Some may think it won’t produce as much energy as a 1000W light. However, its PPFD value can reach 1813 μmol/m2/s while some 1000W grow lights emits almost the same PPFD value around 1800μmol/m2/s. (It’s easy to search on websites)
So while the 650W system has a lower wattage, it emits the same amount of PPF as the 1000w grow light. That means, it produces the same grow result as 1000w light does.
In the long run, the 650W system will pay for itself, while the 1000W system will end up costing more to run. That’s because the 650W will use 780 kWh for one complete grow while the 1000W system will use 1200 kWh per grow.
If the average US household pays $0.15 per kWh, then the 650W LED costs $117 per grow while the 1000W costs $180 per grow. And take into consideration of a 5-year running cost (Mars Hydro promises a 5-year warranty), this 650W LED grow light will save you 945USD in total! And it promises high-quality output at the same time!
Then why not choose a low running cost with the same grow results LED grow light?
One of the primary measurements to see how well a grow light works is to see how many grams per watt you get after a harvest.
Individual growers can usually achieve 1.8-2.5 grams per watt while professionals can get 2-3.5 grams per watt. Only high-quality LED grow lights will be able to deliver a high amount of grams per watt.
For example, Mars Hydro’s FC series have a gram per watt measurement of 2.5. Real feedback from customers has found that the FC-6500 was able to reach a whopping 3.9 grams per watt.
Just be careful of any ridiculously high gram per watt measurements from shady manufacturers that have no verification.
Everything we explained may seem like a lot to remember, so Let’s reshow and make a full conclusion.
Excellent LED chips are from Samsung, Osram, Bridgelux, and Epistar...Remember a real LM301B chip will cost $0.2 to $0.4 per chip.
Likely, the cheap LED grow lights that are packed with inferior LED chips won’t produce the right wavelengths of light and have subpar performance. In the end, you get what you pay for.
A light use good brand chips does not simply mean it uses the best chip model. Remember to always look at all the details and choose the most efficient chip models.
Let’s take a closer look into Samsung chips. Samsung 2835(LM281) model line is much less efficient among all Samsung planting LEDs. The most efficient line is Samsung 3030(LM301) line. While the Samsung LM301D LED chip in the 3030(LM301) line offers the least amount of energy of Samsung’s 3030(LM301) LED chip line. So buyers beware that when a light claims to be a Samsung chip, ask the vendor chip model and choose Samsung 3030, and choose LM301H and LM301B for the better.
When you find two good lights using the same brand chip and the same model, it’s time to check the LED chip quantity.
As we already learned, LED chips are the most costly part of an LED grow light, and lower chips & higher wattage are a recipe for overdrive and a lot of heat. That means that the light likely won’t last very long and produce inferior results after a short time.
So what if two different multi-bar style LED grow lights are similar? What if they have the same good LED chip brand, model, and have a similar LED chip quantity? And even the same PPE like 2.7-2.8μmol/j?
For the final tiebreaker, you need to look at the PPFD map. As we explained earlier, PPFD is extremely important and many LED grow lights have an uneven PPFD.
For example, if we look at the Mars Hydro FC-6500, the PPFD map is completely uniform, delivering roughly the same amount of light to the entire grow area.
Remember to always invest in PPFD instead of wattage. The right PPFD value will give you more bang for your buck while a high wattage but very low PPFD light will only increase your running costs.
And remember that light vendors often tell lies about PPFD value. So it’s best to find out from other users. Their true story cannot be a lie.
Check Mars Hydro FC-6500 grow result. One FC-6500 produces 4.5 pounds result.
Are There Any Budget Options?
If you’d still likely to grow like a pro but want something a little cheaper, then you’ll need to find an LED grow light that uses another reliable chip brand.
For example, the Mars Hydro FC-E series are budget-oriented multi-bar style LED grow lights that are made with BridgeLux LED chips. Bridgelux is another high-end LED chip brand and the FC-E6500 has almost 4,000 BridgeLux chips running at 650W.
However, after cultivators find its efficiency and advantages, the price of BridgeLux might go up. So be hurried.
We know that this seems like a lot to consider for making a purchase. However, getting a high-quality multi-bar LED grow light is an investment.
You're investing not only in the light itself, but the quality of your future grows. Getting a subpar LED grow light will only lead to more costs and more problems further down the line.
Getting a more expensive but more reliable system is only going to be beneficial in the long run. Just make sure to follow our tips carefully so you can pick out the best multi-bar style LED grow light with ease.
Thanks for reading. Hope all these tips will help growers find the best LED grow light. :-)