Ideal Distance for 2x 1500w LED Lights

Hey all!

I have got 2 x King Plus 1500w LED Grow Lights ready for a 4x8 tent (of which I will be using 4x6 to scrog 6 plants in rdwc setup).

On the product page, it says 2-3.5ft distance from plants would be ideal but that sounds a bit too far away to me, at least for later stages of plants. There are many contradicting information for ideal led light height, and almost all suggest closer than this. I know it all depends on the brand and model but what the company suggests just may be the safest point where you don't get the best outcome that you could have... though I'm not sure and kinda worried I might light burn the ladies if I get the lights closer than they should be.

There is this image on the product page, which doesn't mean much to me so I thought it'd be better to ask you guys for some help:



I will be using only the veg switch for the first 1.5-2 weeks, and then switch bloom on as well for more light. My plan was to keep the distance at 30" at first, and later gradually lower it down to 18"-20" by the end of the vegetative stage to be kept at that height till the end of flowering. I will be keeping the stretch under control with a trellis net as much as possible anyway. But looking at the above image, do you guys think that this might be dangerous for the plants?

I know the PAR value shouldn't be less than 100 at any time, but what is the most that the girls can handle?

Any help and sharing of experiences are appreciated Thank you...

Those lights are probably around 250 watts actual. With 500 total watts LED you probably want somewhere between 3x3 and 4x4. A little low for a 4x4 and a little high for a 3x3. 18 to 22 inches at all times is what I would do..and with any undesired stretching or if I wanted much bushier compact plants I would run both switches whole grow.

dbz said:

Those lights are probably around 250 watts actual. With 500 total watts LED you probably want somewhere between 3x3 and 4x4. A little low for a 4x4 and a little high for a 3x3. 18 to 22 inches at all times is what I would do..and with any undesired stretching or if I wanted much bushier compact plants I would run both switches whole grow.

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Do you mean that running the bloom switch on would actually limit my stretching during veg as well and not actually help it grow faster for filling the scrog net although I’m giving more light to it?

vorus said:

Do you mean that running the bloom switch on would actually limit my stretching during veg as well and not actually help it grow faster for filling the scrog net although I’m giving more light to it?

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More light tends to equal less height. I ran 420 watts on current grow full from sprout to now 6 weeks in flower. Never had a problem til this past week where i think the two tallest colas in the middle got a bit of burn and raised the light a bit with some doing (grew some heavy sativa stretchers and basically ran out of room)
Edit: There is a point of less return with light though without factors like upped co2 for instance both of those lights with both switches on in a 3x3 would probably be too much during veg, but not a 4x4. In such a case you could just raise the lights a few inches.

Bro I always keep both on and I run meter square. Not the same light but similar

dbz said:

More light tends to equal less height. I ran 420 watts on current grow full from sprout to now 6 weeks in flower. Never had a problem til this past week where i think the two tallest colas in the middle got a bit of burn and raised the light a bit with some doing (grew some heavy sativa stretchers and basically ran out of room)
Edit: There is a point of less return with light though without factors like upped co2 for instance both of those lights with both switches on in a 3x3 would probably be too much during veg, but not a 4x4. In such a case you could just raise the lights a few inches.

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Oh I see... plants do not try so hard reaching up to the light since there is too much of it, from what I understand.
So, yeah I’ll be basically growing in a 4x6 space so it’ll probably be more than enough to make the most of the lights without upped co2 as well. Though I was considering some diy methods for upping co2 by hanging a lose cap container with some yeast and sugar in but I’m not sure if it’ll be worth it.

scoobyboy said:

Bro I always keep both on and I run meter square. Not the same light but similar

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Even during seedling stage?
What wattage is your light? Could you please share the height you hang it from if it’s similar?

vorus said:

Oh I see... plants do not try so hard reaching up to the light since there is too much of it, from what I understand.
So, yeah I’ll be basically growing in a 4x6 space so it’ll probably be more than enough to make the most of the lights without upped co2 as well. Though I was considering some diy methods for upping co2 by hanging a lose cap container with some yeast and sugar in but I’m not sure if it’ll be worth it.

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That is not enough light for flowering a full 4x6 well.
At most 4x4 and even then a little light for flower.

dbz said:

That is not enough light for flowering a full 4x6 well.
At most 4x4 and even then a little light for flower.

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You got me worried and I’ve been reading reviews all around... users generally seem to be pleased with how well their grows are even in bigger tents or less watts in similar tents with this model. But I’m still worried as you sure seem to know what you’re talking about... I just hope you are wrong

Sorry bro for late reply I use 150w led to veg clones for approximately 2 weeks ,then put under meizhi 548 w (stated actual power draw) led after about 2 weeks at 24 hours a day. Then hit the switch . Works amazingly well. Not gonna lie I was 100% air cooled 600’s. And they still pull the good shit but I wanted to try these “blurple” lights as experiment and they work. All I say is seedlings don’t need mega light so give 24”. My next grow is with 480w qb I’ll see what this Samsung stuff is all about!

Also forgot to say 1m sq is the area! ..... damn amnesia haze