How many squared feet does a plant need? (Indoors)

If i had a LED that covers a space of 5’x4’ how many plants could you place in that space? Not looking for an exact as i understand LST and many other factors come in to play, but just to give me an idea.

Textbook answer = 2.5 feet . LST would do well in you space. # of plants depends and # and size of containers - 4 plants - five gallon containers would work — if 3 gallon (really to small) 6 plants ----- 10 gallon - 2-3 gallon. Just asking - type of lighting are you going to use

1 Like

Hoping on using a P1200, for both veg/flower

Can someone explain difference between “max coverage and core coverage” of a light? I.e core coverage= 5’x4’ and the max coverage= 6’x5.5’

that purchase LED grow lights are doing so with the sole purpose of growing cannabis for personal/medical use. I know this and, most importantly, other LED Grow Lights manufacturers know this as well so why do most of the published coverage areas seem out of touch with reality?

LED Grow Light Coverage

While some grow light companies flat out overstate their recommended growing area simply to dazzle the visitor into purchasing, others have not-so-sinister reasons for their claims. The former is out to make a quick buck – customers be damned – and they end up shooting the industry in the foot by perpetuating negative reviews. This is especially true of low-wattage LED panels and spotlights. The latter is trying (sometimes to the detriment of its bottom line) to keep neutral by not catering to any particular customer niche, i.e. Cannabis Growers.

Coverage area varies widely depending upon many factors:

wattage of individual diodes
shape of the grow light
degree angle of the diodes
overall wattage of the light
intended usage
. . . the list goes on
Of all of the reasons coverage is affected, the most important is its intended usage. You see, many manufacturers publish coverage areas based on the vegetative stage. This is a very important point. When plants are in the vegetative stage, they need less intense lighting than in the flowering stage. As cannabis growers already know, getting plants successfully through the vegetative stage with LED Grow Lights is pretty straight forward at this point. It gets tricky when bringing your plants through the flowering stage successfully due partly to the fact that some lights are just not up to the challenge. More importantly manufacturers are eager to show clients a huge savings in electricity (thus justifying the higher entry cost) stating a 100W LED grow light can support a gardening space of 3’x3′.

Let me be blunt here – a 100W LED grow light CAN support a 3’x3′ footprint but only during the vegetative growth of plants like lettuce, herbs, and some fruits and vegetables. If that is what you are wanting to grow then you will do just fine. For those of you growing cannabis, coverage expectations need to be put in check.
Loose Cannabis Bud

Big Grow Space – Little Light, A Recipe For Disaster

A common complaint about LED Grow Lights among cannabis growers is that they just don’t get the yield they were expecting as compared to their previous grows using HID lights. Or things might look great when growing – big leaves, tons of buds – but comes up short on dry weight due to light, airy buds instead of the thick, dense buds they may be used to.

If your buds are looking like the wispy little nug on the right, then your issue could be that you are trying to grow more than your light can handle. Trying to force that 100W LED grow light to fully flower all your plants in a 3’x3′ space is never going to work.

What you need to do is reduce the coverage area – generally by 30-50% – of what a manufacturer states the light can handle for the common gardener growing flowers or herbs for cooking – i.e. vegetative growth. So now you can use that 100W LED grow light in a 2’x2′ space (enough for a couple decent plants or even a SOG/SCROG) and come away with thick, dense bud as you see in the picture below on the left.Dense Cannabis Buds

LED Grow Light Coverage Area Guide

I have already stated that there are many factors that can affect the coverage area of LED Grow Lights, here is a rough guide to what I think are suitable grow spaces for a given wattage of light. By keeping these guidelines in mind with your growing effort, you will find that your results will match or exceed your expectations.

Light Wattage Vegetative Stage Coverage Flowering Stage Coverage
100 Watt 2.5′ by 2.5′ 2′ by 2′
150 Watt 2.5′ by 3.5′ 2 by 3’
225 Watt 3.5′ by 3.5′ 3’ by 3’
440 Watt 4′ by 4′ 3’ by 3’8:


Hi will, thanks for clarifying!
The light I intend to by is

this one. As the wattage is higher than those that you stated, can ypu please give a quick review into the best way this light can be used. It is a trusted brand that has claimed that this LED can replace a “1400w HPS”. A claim that i profusely disagree with (but in saying that. I could be proved wrong).

Good light choice but have you consider the Diamond series or the XTE , try calling Advance and give them your grow tent size and they will give you the best options for your budget and also the light heights . But if you have a 4x4 tent I’ll run 2 diamond series 350 or 2 XTE series 300 and that would be about the same price for that one light , which I believe that Platium is an older model .

I have very little light knowledge and will be easily mislead! But by the info i read the P1200 was better than what I thought was its equivalent. The DS XML 650. But again I wouldn’t know lol! I wont be using a tent for my grow, ill be using a shipping container, or a grow frame ill build myself, so i cant really tell you what light i need as i don’t even know the space it’ll be illuminating!

2 Apache Tech AT600 will be your best investment for that planned strategy .

Damn thats a mean price tag!! Outstanding looking light though! Seemed to have a small “foot print”?

The best you can buy I believe .

1 Like

Not sure if thats in my budget atm, maybe soon i guess

Hi @yoshi, was reading through the specifications of the light you recommended and i ran into a hitch, it asks you to choose between “light spectrums” as i do not think it is full spectrum but for single purpose. In your opinion what would you pick? I thought the white/red 3:2 medicinal option was most suited for an indoor cannabis grower but i am unfamiliar with what light spectrums Cannabis thrives in.

4:1 would be better for full cycle grows .

Yeah that makes sense.

I’ve got to tell you this is the greatest light!!. With a P450 and he loved it so much that he went straight to the P1200. He just purchased his second P1200. Not a man of much science, but he does know what responsive plants are. The stretching stopped. The plant is clearly growing at a rate he had never seen. The veins in the leaves are more defined. The leaves are darker green and the vegetation is dense. The root ball is enhanced (can see it when transplanting). The node spacing on the plant is closer and overall the plant is more robust. Been using these lights since early November. The first girls were just put in to flower about 10 days ago and you can bet I will follow up with the results, but my expectations are
high. He? was doubtful because of all the double speak and attitudes about LED out here, so He original bought the 450 so he couild growr his babies under the veg light of the P450 side by side with Hydrofarms 8 bulb 400 watt T5. Same clones, born the same day, same soil, same food, same cycle. Only the light was different. In veg mode, at 137w in veg mode running the P450, that is 263 LESS watts burning that the T5. They responded with nearly double the growth rate. While the others are still in veg, the three he raised under the 450 are in the flower room at day 10 under the P1200. That’s right, 27 days from birth to flower light. He is going to replace his entire lighting system with these lights. No ballasts, compact, easy to mange and clean. The fans are noisy, but no noisier that the 750 CFM I cool my 4 1000 HPS with. The HPS don’t know it yet, but in his
¿room…their days are numbered. Outstanding light for all stages of growth. I would highly recommend it. I got dizzy reading…par, lumens, watts, nanometers…Ihe justt had to try it and see. For the price and the warranty…the savings on bulbs and power, the exceptional response of the plants…this light is for me. My bro saw the response of his plants, got jealous and is going right out to buy one too.

A follow up for my friend in OR…two pics. Same girls…4 weeks into 12 hours. 9 weeks old…01-01-16. Node space is averaging 1/2". He pinched and trained them as they went. Healthy, same amazing colors, leaf definition, drinking and eating more and faster than anything I have ever grown. I am ordering two of theseh lights myself.

So I highly recommend this light and it with
Out perform the H.P. S .

B Safe


Thankyou will! Thats what i needed today! If you can tell me some specifications like “how many plants under 1 p1200, and how high to have it” you got me sold brother!

Well that’s an easy one yo answer. Lol
Rule of thumb is …if it hurts your hand… then its to close to your
Plants. So you move it up.
How !any plants depends on the size of your grow room.
An average plant needs one square foot…

B Safe


Core light is where you get the most effective light. I personally grow 2 plants per 4ftx4ft tent and they fill it up nicely without growing into each other.
I had heard that the back of the hand test isn’t reliable for LED due to how the light is concentrated per bulb. Maybe @How many squared feet does a plant need? (Indoors)

1 Like

So pretending I have 5x5ft space, i could have 5 plants? I heard the very same thing, that test is unreliable for LED’s but never leard how else to guess hight. Thanks!