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Comparison of MH and LED light for mango growth

yellowthumb
12 years ago

Guys,

This maybe a subject that only interest those northern mango lovers. We just can't plant a mango in our yard and use the mother nature sun light.

I have a Lancetilla mango that is growing like a weed for me. It's quickly overgrowing my 1000W MH growth light, well, at least outgrow the portion that it deserves. So only half the mango tree is under the 1000W light. The other half is shaded. A week ago, I added a LED growth light just for the remaining half. The MH side light density is twice the LED side.

The LED side is growing really differently than the MH light portion. The new growth on the LED side is so much more compact, there is very little stretch between the nodes, at least twice as compact. Plus the tender growth hardens off a lot faster, for a mango, I mean the new growth thickens up. It took over a week under my MH light to harden off a new growth, but for LED, it took 3 days to reach the same stage. The leaves are still drooping, but just very thick and fat. Finally the LED side leaves are much bigger.

I will try to take a picture recently.

Comments (18)

  • nullzero
    12 years ago

    How many watts of LED lights are you using? Are you using Mylar to increase the reflectivity in the area? The lower powered LED lights are good at starting seedling vegetables. I am sure mixing up the lights is only beneficial to your mango tree, since it will be getting different spectrum of light.

  • ohiojay
    12 years ago

    Very interesting indeed. Thanks for sharing this. Look forward to the pics for comparison.

    Jerry...you are using LED's also. Are you noticing any differences?

  • stressbaby
    12 years ago

    My mango isn't getting any supplemental light in the winter at all. It's flowering like a $# right now tho. I'll be watching this thread for updates...

  • lycheeluva
    12 years ago

    i use both led and MH but there is no way to compare as my led is 90w and the MH is 1000 watts and one is directly over a lychee and one's directly over a mango. so really no way of telling.

  • yellowthumb
    Original Author
    12 years ago

    I got this LED light from ebay. It's marked as 240W, but it's misleading since 240W is not the actual power output. The vendor defined a teminology that I don't understand, Line Purity. So YMMV. Some people reporting actual output from 120W to 150W. But my power meter reads about 3000 fc for a one foot distance. That's really good for a LED, almost beats my CFL. The downside is that the light angel is really, really narrow, so it only covers a small area.

    What interesting to me is that LED could dwarf my mango tree in pots.

    I am going to take pictures tonight. Keep tuned.

  • jsvand5
    12 years ago

    I don't use LED's for my plants, but I do on my fish tank. I am using higher end LED's than what they use in the lights made for plants. If you are a little handy you can make an LED system that will blow away the output of HPS bulbs. The problem with the lights they make for plants is that they use cheap 1 watt LEDs. They now make 3 watt and even 10 watt leds that put out an amazing amount of light. The technology is evolving so fast with them that the light that I made a year ago is already pretty outdated but it's still strong enough to burn your eyes if you look directly at it. Found that out the hard way.

  • samuelforest
    12 years ago

    I prefer using the HID, I feel more comfortable with this old technologie, even weed growers prefer them LOL :).

    Samuel Forest

  • ohiojay
    12 years ago

    Seeing as how much we northerners must spend already on heating and lighting, the idea of the monthly electric bill going down is appealing. However, the bigger LED units that actually can cover more than a couple of square feet are still incredibly expensive. Every manufacturer claims how little to no heat is produced yet each of the larger units are equipped with internal fans!! An equivalent unit to a 1000W metal halide system is around $1200 and the 600W is around $600. Even with these larger units, the coverage is a pretty narrow area...especially when needed for blooming and fruiting.

    I'm interested in what John is suggesting. I know it is possible to build your own but wonder if it is really cost effective. The other thing to consider is getting the correct ratio of the different spectrums in order to promote growth, blooms, and fruiting.

    I found the following conversion from HPS/MH to the equivalent LED system:

    HPS Wattage\LED Wattage
    400W \ 90W
    600W \ 180W
    1000W \ 350W
    2400W \ 700W

  • samuelforest
    12 years ago

    Don't buy a 1200$ unit! I use a 400w bigh bay or warehouse metal halide light. It's a lot cheaper and works as well as a 1200$ unit and it cost me only 20$ with the bulb ;). Of course they are used ,but for the price it worth. I know they are heavy and you can't put them up and down as the tree grows ,but I found a way to do this. You just need to separe your ballast and the socket and this modification cost about 25$ ,but make sure you don't use an extention cord in between the ballast and socket! You need to use BX, otherwise your house will burn!

    Samuel Forest

  • yellowthumb
    Original Author
    12 years ago

    I only spent less than 500 dollars for the 1000W MH light system. It's a digital ballast, high quality, and a Phillips 1000W MH light. It's so much better and cooler than my old ballast.

  • lycheeluva
    12 years ago

    my light system is a 600 Watt High Pressure Sodium and a 400 Watt Metal halide

  • jfernandez
    12 years ago

    Nice set up Sam!

    Which is your Mallika and Lancetilla? Your anona leaves do not look like a cherimoya what variety is that?

    JF

  • tropicdude
    12 years ago

    Another factor to take into consideration is the wavelength of the light.

    I have noticed LED lighting for hydroponic use, that use red and blue LEDs supposedly at wavelengths that plants prefer or use more efficiently.

    It makes sense to concentrate all your energy into parts of the spectrum that plants will use most. anything out of those wavelengths is just waste.

    Here is a link that might be useful:

  • ohiojay
    12 years ago

    Samual...the whole point to switching to LEDs is the cost to run them...not the cost to purchase. Also the reduced heat. All of this equates to more usable light to the plant rather than being lost thru heat. The MH/HPS systems are still expensive but cheaper than the LEDs by far.

    A warehouse MH bulb is not going to deliver the proper spectrums of light as a bulb specifically for plant light systems. Still some benefit but no where near as it could be.

    The $$ figures I mentioned above were for the LED systems, NOT the MH.

    I love the results my MH system delivers, but the cost of running it and the heat build up has convinced me that it will be my last such system.

  • samuelforest
    12 years ago

    JF, I don't understand what are your talking about because it's YellowThumb setup :), but I have a Mallika mango tree.

    Ohiojay,I know led spectrum is better ,but still a thousands dollars.LED are good, I'll maybye buy a unit someday when they will be cheaper. Even if the LED have a better spectrum, Hortilux is making a bulb with a light spectrum really wide (lots of red and blue). The name of the bulb is Hortilux blue if someone is interested

    The light spectrum of my bulb is 4000k (I changed it, it's not the stock bulb),so it's great for vegetative growth and most of the MH bulbs have a 4000k spectrum. Also it cost me me about 10$ a month to run my 400w mh about 12 hours a day, so this not that expensive for me.

    I love that MH throws heat because it heats my garage, so it's less expensive to heat :).

    Samuel Forest

  • yellowthumb
    Original Author
    12 years ago

    Ohiojay,

    LED is expensive. The wife has been wondering why not buying a big screen TV, actually cheaper.

    The cheapest LED I found so far for 260W to 350W pure light output is around 580 dollars with shipping and handling included. But I am still not convinced with its coverage. My LED only covers a 2 by 3 feet area.

    Sometimes heat can be beneficial, it dries up the soil faster. But once the weather warms up, it becomes a problem.

    Some LED experts admit that the LED efficiency is overrated. The actual efficiency between LED and HPS is around 2 to 1 or 1.8 to 1. So if you have a good 1000W HPS, expect to put 500W pure LED output there to beat the HPS.

  • JOHN CARSON
    3 years ago

    This thread is interesting because i just brought my mango saplings indoors under a 1k watt led. Just transplanted from spring sprouts and hoping they will love my humid 75 degree fish/green room.

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