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Is my light close enough?

keith1975

Well-Known Member
I bought the typical Apollo 8 chinese led lights. I didnt know they were chinese at the time, as they are sold by reputable supplier. But somehow these lights arent half bad. Or so I think. I had a super cheap Chinese light in there as well, and it seemed like the plants under it grew slower. My lumen meter also said it was under 1000 lumens. When I use the Apollo's, I get over 2000. But according to this, I need this:

> 1. Minimum amount of lighting needed is around 2000 lumens per square foot.
> (Two – 23 watt CFL’s, per square foot*)
> 2. Mid range is around 5000 lumens per square foot.
> (Three - 23 watt CFL’s, per square foot*)
> 3. Optimal is 7000-7500, or higher, lumens per square foot.
> (Five – 23 watt CFL’s, per square foot*)

This is the reason I brought the lights closer and burnt them to a crisp. I thought I should try and get lumens in the 5000 range. But that killed my plants. (along with other factors)

I asked the manufacturer and they said 30cm to 60cm away from the plant. But that doesn't help me really. Isn't there some sort of mathematical way, or device other than a lumen meter that can somehow tell you exactly how far to place the lights?

My concern is that I have now placed them fairly far away, and the plants are growing well, but what if my buds are weak because I'm not giving them enough light? I dont want to only find that out at the very end.
 

StoneOtter

Member of the Month: July 2019, Sept 2020 - Grow Journal of the Month: Nov 2019 - Plant of the Month: April 2020
Hi Keith, glad you asked. I have the same issue with lighting. Very little guidance is given especially the inexpensive ones. @Kingjoe83 has some new lights he's using and was looking at lumens and luxes. Check his current journal out. I use cob lights and almost never get them closer than 24 inches.
 

keith1975

Well-Known Member
Hi Keith, glad you asked. I have the same issue with lighting. Very little guidance is given especially the inexpensive ones. @Kingjoe83 has some new lights he's using and was looking at lumens and luxes. Check his current journal out. I use cob lights and almost never get them closer than 24 inches.

24 inches, that would kill a massive chunk of my grow area if I have to keep it that far til the end. But I use LED, so they should be able to go as close as 30 cm as the manufacturer suggested. Just really wish there was like a par/lumen meter... that's what they should call it, a PARLUMENETER. That tells you your lights are too close or your lights are too far. Or maybe even "these lights are too weak, get better one's".

Will def checkout the journal! Thanks for the tip!
 

KingJoe83

Grow Journal of the Month: July 2017
24 inches, that would kill a massive chunk of my grow area if I have to keep it that far til the end. But I use LED, so they should be able to go as close as 30 cm as the manufacturer suggested. Just really wish there was like a par/lumen meter... that's what they should call it, a PARLUMENETER. That tells you your lights are too close or your lights are too far. Or maybe even "these lights are too weak, get better one's".

Will def checkout the journal! Thanks for the tip!
Hey buddy
Ill pm ya buddy
 

Mars Hydro

420 Sponsor
The Appollo leds are same as the old version LED grow lights, so the hanging distance should also be the same as ours:
- seeding: above 24''
- veg: 18~24''
- flowering: 12~18''
Hope this helps! :green_heart:
 

LEDXpert

Active Member
For veg its a brightness issue, don't want it to bright. Will only know that by a proper meter.

For flower its as close as possible without burning or at the height that maximizes your optics if you have optics. If you have like a CBL style light with COBs on it you probably have optics. You can take a large piece of roll paper or a bed sheet with a partner and stretch it out and raise it until you see the beam pattern you like hitting the surface and than then note that height. Then maybe drop a piece of yarn or something non-flammable from your light with a washer tied to the end so you can always know your optimum height so it is easy to track your canopy.

Or if you are feeling lazy, take Sara's advice. It seems like she knows about your light.

You can't really give it too much light in flower and if you can then you can decrease your photoperied. Energy in --> grams out will track fairly linearly to about 1000umol/m2/s and then start seeing diminishing returns, but as long as the plant is cool enough it will be okay. Increased photosynthesis rates may require additional CO2 above 600umol/m2/s. Based on the light you said you have I can just tell you that you will not be reaching this level of output for either condition.
 

Emilya

Member of the Month: Mar 2019 - Grow Journal of the Month: Jan 2020
This really is a problem and we are almost forced to do this by trial and error once buying one of these new version chinese LED arrays. I really believe that the quality is there in some of these lights and the price has dropped down to rock bottom, but I too after moving from HID lighting, wonder if these little toy lights are doing what they need to be doing.
I am becoming convinced by the day however that my light is stronger than I give it credit for. I have a new name chinese 1000w full spectrum array about 15" away from my young veglings, and they are going crazy with growth. The problem is that I, like you all, feel like I am just guessing, and I feel uncomfortable going simply by the manufacturer's recommendations in seedling, veg and flower stages.... but what else can I do? Does someone at least have a PAR chart showing what levels are appropriate at the various stages of our plants? I know what this manufacturer's chart says, but can I trust it?
 

KingJoe83

Grow Journal of the Month: July 2017
I covert lux to ppfd myself and use a 45$ lux meter that ranges up to 200000 lux .

For veg I was told 20-40 thou lux needed so does it like light lower lights until they reach and are happy with light . Flower 40-70 thou lux needed in flower . However from
My calculations around 59000 thou lux in my tent space would be the same as 1000 ppfd if it mistaken .
 

Mars Hydro

420 Sponsor
Very useful! Thanks!

Are the apollo lights not that great? Any reason to be concerned? Will my buds be weak?
I prefer not to talk about our competitors, lol As long as you follow the right guide of using lights, such as 35~50w/sft, your power enough, and hanging height right, right ph, nutrients, etc, should not work out very bad. :green_heart:
 

keith1975

Well-Known Member
I prefer not to talk about our competitors, lol As long as you follow the right guide of using lights, such as 35~50w/sft, your power enough, and hanging height right, right ph, nutrients, etc, should not work out very bad. :green_heart:

If I do everything right, will my bud still be "Acceptable" potency? If it's going to be weak, then I need to buy other lights, or more lights.
 

grow boy420

Active Member
I bought the typical Apollo 8 chinese led lights. I didnt know they were chinese at the time, as they are sold by reputable supplier. But somehow these lights arent half bad. Or so I think. I had a super cheap Chinese light in there as well, and it seemed like the plants under it grew slower. My lumen meter also said it was under 1000 lumens. When I use the Apollo's, I get over 2000. But according to this, I need this:

> 1. Minimum amount of lighting needed is around 2000 lumens per square foot.
> (Two – 23 watt CFL’s, per square foot*)
> 2. Mid range is around 5000 lumens per square foot.
> (Three - 23 watt CFL’s, per square foot*)
> 3. Optimal is 7000-7500, or higher, lumens per square foot.
> (Five – 23 watt CFL’s, per square foot*)

This is the reason I brought the lights closer and burnt them to a crisp. I thought I should try and get lumens in the 5000 range. But that killed my plants. (along with other factors)

I asked the manufacturer and they said 30cm to 60cm away from the plant. But that doesn't help me really. Isn't there some sort of mathematical way, or device other than a lumen meter that can somehow tell you exactly how far to place the lights?

My concern is that I have now placed them fairly far away, and the plants are growing well, but what if my buds are weak because I'm not giving them enough light? I dont want to only find that out at the very end.
economics of light output is also a factor..to some of us..ie a close cold CFL might out perform a distant more expensive light system..its all about trial and error..and evaluating tour electric bill.
 
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