No bs light question

Discussion in 'Growing Marijuana Indoors' started by txbud997, Feb 10, 2018.

  1. So I have a 4x2 tent. I have no reason to want a bigger space to grow anytime soon.

    right now I have a hlg260w.

    What I'm wondering is, what is the max amount of usable light I actually need for a 4x2 space to flower?

    This 260w is pretty damn bright. But would I really get anything more out of adding more to it?
     
  2. Forgive my ignorance, but what is an hig260w? Does it pull 260 actual watts?
     
  3. I would consider how many plants you'll be growing instead of the size of your tent to determine how much light you'll need. You'd need a par meter and decide how you want to grow. Are you going to max out par, add co2 and have a specific heat and humidity schedule or do you want to get by with giving your plants what they need to grow but without adding all the other stuff to get the extra benefits?

    If you want to max out the par to your plants, Co2 would make them benefit from increased production. If you dont then your nutrients are where you want to look for the most benefit out of your plants. I would look at your lights ppfd to see their recommended par and then measure the footprint of the light at that height. That'll give you a good idea of how much light you'll need per plant.
     
  4. Just want to give them what they need without getting crazy with CO2.

    Just lights, a fan and nutes
     
    • Like Like x 1
  5. I respectfully disagree. How would you determine the amount of light required if the OP wanted to do SOG and grow twelve plants? Would that require more light than having 2 plants that are LST'd? The amount of light is determined by the square footage of your grow area. The OP has 8s/f of grow area - 300-350 actual watts with LED and 400 watts with HPS would be the standard.
     
    • Agree Agree x 1
  6. Perfect for a 4x2? or would it make any real sense at all to put more light in that footprint?
     
  7. That light is perfect for that grow space. The footprint is even the right shape. It's extremely efficient. 25% or more efficient then a 400 watt hps. That led is around 177 lumens per watt. It will work fine at that power level. That is plenty of light. The qb260 is about 285 watts at the wall with lose in the driver. They are 260 watts at the boards hence the model number.

    I wouldn't add more light myself. At full power with the limited headroom most 2x4 tents have it should be almost too much for some plants.
     
    • Like Like x 1
    • Agree Agree x 1
  8. The amount of light in a grow space can also be measured by a par meter. Which i suggest you have one. Led lights if you dont have a par meter vary widly in their par. Thats because not all leds are the same. I gave you the recipe to find it if you dont have a meter. Hlg has some good ppfds so you can tell how much light youre going to need.

    To find out exactly how much light youre giving plants, youll need a par meter.

    That post before is also considering if youre trying to max par or just get adequate growth.

    For that light, youll want to keep it at about 16 inches to max par for one plant. The footprint is not that large so if you want to max out par to more than one, youll need another light BUT if you only need adequate growth the this one light should be plenty for however many plants you want in that tent.

    In fact, here is a video with par for your specific board.

     
  9. right on. It is pretty damn bright. Was running hot turned all the way up. But I dialed the driver down slightly and took the driver off of the top of the light=much cooler
     
    • Like Like x 1
  10. Par on the qb260 at 18" with only 3 sides of white poly in the center is 1160. It dies out to about 700-900 range at the corners 2 ft range. In a good mylar tent the numbers would be slightly higher.
     
  11. I'm going to lean with the numbers from the video. At 18 inches, the mid barely registers 1000 and 300 on the corners. If you're maxing out your par, you'll need more than one for more than one plant unless you somehow keep your canopy less than 2ft wide. Even in SOG, you'll only be maxing par to the middle. You'll need more than one light to do that adequately.
     
  12. 1160 is the number at the center from the video. No way you can put a second qb260 in a 2x4.

    You're looking at the par charts for the other lights. He tests 3 lights in the video. The qb260 is about 700 in the corners.
     
  13. Here's a DE 1100 watt bulb shootout just for comparison. It may be different distance but that is how commercial DE fixtures are designed to run.
    [​IMG]
     
  14. Par isn't everything. My platinum p900 will out par my qb260's but the white light spectrum of the qb's is just more healthy for plant growth and per watt they are more efficient. The p900 will do over 1400 in the center.
     
  15. They seem to have no problem covering a 4ft spread for me. This was my last crop of 3 plants before I cut the one in the front down.
    IMG_8831.JPG IMG_8835.JPG
     
    • Like Like x 1
  16. The qb 260 is perfect for that footprint.
     
  17. I grow in 2x4 closet
    2 blackdog 200 is perfect for me and my footprint
    More not needed nor would improve anything
    Less would not be acceptable anymore
    They each draw about 200w
    Probably each light comp to a 300w hps
    If one went out today I would buy another one
    I can't improve my plants with any more light, so even if I have overpaid or even have excess light not needed or used by plants the savings in cost would be minimal compared to the risk of changing perfection.
     
  18. Running 2 cheap 1000w(2x250w actual) (500w) Asian generic LEDs (100x10w diodes each) in a 2x4, almost 3 ft from canopy. These lights cost me less than 100$ a piece and I couldn't be happier right now. I almost want to lower them but fear bleaching. Buds are growing slow n dense and tricks are going crazy. Can't beat it in my opinion

    Sent from my Z982 using Grasscity Forum mobile app
     

Share This Page