Hi dear Oak, Thank you so much for your guidance. Dear Oak I have a other question, How much space (grow tent) and how many watts (T5) is required to 50 to 70 plants at seedling stage?
And do i have to allow more questions?
I made a mistake and re-did it
Will
Mazoo,
Determining the ideal wattage of your grow light is critical for a successful indoor garden. The wattage determines the strength of light supporting your plants.
It is recommend that you provide your plants 50 watts of grow light per square foot in the growing area. Insufficient light will result in unhealthy leggy plants that produce low yield.
Your grow area would be 10 x 20 = 200 sq. You would need 24,000 watts to grow 50 plants
So this took me half the nightā¦lol ITāS LARGE SO CUT AND PASTE IT IN YOUR FILES
How Many Light Fixtures Youāll Need ?
Lighting is a very important subject for work shops. Poor lighting can hinder your productivty, cause eye strain, and probably most importantly ,can compromise your safety.
The industry standard for general lighting in a room is 50 foot candles per square foot.
To determine how many fluorescent ceiling fixtures you need, a formula is needed to determine the number of lumens needed.
A couple of pieces of information are needed for the formula.
The square footage of the grow area. Length X Width .
The Lumens per fixture.
The co-efficient of usage.
Light loss factor.
Each plant needs one sq. foot or 50 lumens per sq. foot.
So Iām using 50 plants in an area of 200 square feet
For this weāll use a grow room that measures 10x20 feet.
Sq. Ft. = 10x20= 200 sq.ft.
Multiply your sq. ft. (200) by 50 lumens. Since 50 lumens are needed for every sq. ft., this will give you a preliminary number for total lumens.
200 x 50= 10,000 lumens .
That is the minimum amount of lumens needed .
There is a light loss factor (.75) and a co-efficient of utilization (.65)
that are added together .
.75+.65 = 1.40
Now we can multiply the minimum amount calculated from above (10,000) * (1.40) = 14,000 (almost there.)
10,000 lumens is then added to the minimum lumens needed to obtain
10,000 lumens + 14,000 lumens = 24,000 lumens.OK
Now we know how much ceiling lighting in lumens are needed. Here is how you determine how many fixtures you need for this 10x20 ft. grow room
As stated above a typical 4 ft. 40 watt bulb has 3150 lumens so a two bulb fixture has 2 x 3150 = 6300 lumens.
So finally we are down to just dividing the lumens of a typical 4 ft fixture (6300) into the total lumens needed (24,0 00) to light the shop to industry standards.
24,000/6300 = 4 I rounded it up to the nearest .
So 4 four ft. fixtures with (2) 40 watt bulbs are needed to light the grow room.
Fixtures Needed to light a 200 ft. grow room = 4 fixtures.
In this casey can stay at 4 fixtures and be good.
This method obviously cannot take into account every grow rm configuration. Some tools will cast shadows and create areas that may not be illuminated as well as they should be. In those cases supplemental lighting can be added.
Also of interest, the height of ceiling isnāt considered in this method. So Iām not sure how the industry derived this formula. Iām sure each grow rm will require some tweeking but this method should at least give some kind of starting point.
HOPE THIS HELPS
WILL
2 Likes
I thought you mite like to have this also. And Thank You for the kind words.
Happy Growing 
Will
2 Likes
Thank you so much for your explanations but I think that you made a few mistakes in calculations. For example, when you are saying that each plant needs to one square feet so 50 plants need to fifty square feet, No 200 square feet. And also in other calculations unfortunately you have mistaken a few times. But doesnāt matter. Anyway, thank you so much for taking the time for guide me and thank you for all youāve done to help me.
@Mazoo ,
Iām sorry but Iām correct. I went with 2sq. Feet per plant to grow. You stated
50 to 70 plants so I roundrd this off to 200 sq. Ft.
But if you want to stick yo 50 plants. Than you would only need two setups with ( 2 ) 4ft bulbs @ 40 watts to cover 100 sq ft of grow space.
Now your 50 plants in 15 sq. Ft. Is never going to happen.
And yes I did make a mistake an said one instead of two. But its based on two sq Ft. which should have been obvious.
Will
Thank you very very much of your again explanations. Do i need 100 sq ft only for seedling stage!!! So how many space do i need for vegetative stage and also how many for flowering stage??? If you look to my question, my question was about space and light for the seedling stage.
I hope to repay your kindness one day.
Your friendship and kind words are more than enough.
My calculations were based on vegg and flower. In flower you wouid want to switch to 600 and HPS or L E D lighting. You can use though t5s for seedlings and vegg The vegg I would go with the H I D for better growth.
OKā¦seedlings will get bigger and bigger so why not be ready. There is more to this than you realize. Youāll need much much more My friend.
2 Likes
Just wanted to weigh in on the size needed for growing 50 plants. I believe that you are going to be needing a minimum of 170 sq ft for 50 plants and 270 sq ft for 70 plants. I have been able to grow in my tent (2x4 feet or 8 square feet) 3 plants that were all fems and stayed below 36 inches tall. It was crowded in there @ 2.6 sq ft/plant. This took all of the room in the tent and as they got mature in the flowering stage, it was difficult to work on them due to not enough extra space to work on the plants. If you are planning on growing 50-70 plants at once, I would plan on a minimum of 3 sq ft/plant to let them stretch and expand during flowering. You will need space to work around the plants. If you are doing Super Silver Haze, they tend to be tall unless you mainline them to keep them short. Thus the 3sqft/plant. I believe these figures to be pretty accurate, at least from what I have grown.
As Garrigan said, there are many other things that are needed such as pH tester, PPM tester, pH up and down, nutrients and a lot more. The lights are a big investment and I feel that LED are great for making nice big and tight buds. My LED has always pleased me ! Garrigan covered them well in the links he posted.
Good luck on your grow and welcome to ILGM. Jerry
1 Like
Hi dear jerry, thank you for the useful information that you kindly provided.
Good day and night
Whether with this space can i go between them and do their works such as water and fertilize them and etc?
All that was in my calculate in my statement
Next time I will list what Iām calculationing on
Less confusing.
Hi,
Incidentally, I like full explanations with an accurate calculation and thank you for that.
I just have a question about the your explanations three days ago. You said, 50 lumens are needed for every sq. ft. Is it correct?
Not sure what you are asking, but I have had my grow tent so full that it was very hard to work on the plants without taking them out of the tent. I do not like to do that, I want to keep them under the lights and growing. What I was saying was that if you are raising that many plants, you will want to get the best results possible. The more you can keep them trimmed and allow light to get the best exposure to the buds, the better the the yield. You can also keep a better watch on possible problems with nutes or bugs. Hope that clarifies, if not let me know. Want to help out as much as possible. Jerry
I want to do plants work inside the tent without taking them out of the tent. So I want to know that is 170 sq ft for 50 plants enough to do the works inside the tent without taking them out of the tent even at flowering stage?
Iām not who you asked, but Iād say if you have to ask a huge NO
It depends on many things like the size of the tents and type of plants grown (some are WAY taller and bigger around than others). I do not remember what your level of growing experience is but it would seem that you may not have enough experience to handle that many plants at once. I would suggest starting with a little smaller grow and you will get the feel for how many plants can go comfortably in a given area. Jerry
I have varieties of fruit gardens(Apple, Peach, Apricotbut) but I did not have any indoor growth.
The growing experience with the fruit trees gives you some experience in growing but, for me at least, growing pot was an entirely different animal. The MJ plants in a tent depend on you for everything, and they have different problems than an outdoor tree will. I raised a garden from 7 to 25 years old until I went into the military. It helped a lot but growing MJ has a learning curve. Start small and work your way up to 50 plants. That many plants is a full time job ! ! Good luck with your grow. Jerry