Confused about advice in LED watts

M

Mintaka3

Member
Hi everyone
I’m new to this forum and I really need help. I’ve been growing for several years under a 300w cfl. Like most people, I now want to change to LEDs but the advice on wattage for LEDs is very confusing,
My tent is small 2x2x4 and many places are recommending lights such as SF1000 which even Spider Farmer promote as being the one for my size tent. As do many other companies… Vipraspectra P1000, Marshydro TS1000 etc. but then I see references saying lights that are 400 or 600 are best and that 1000 is way to strong. Also I found a table that listed 200w for a 2x2 tent
I had actually bought the SF1000 but now I’m wondering if I did the right thing. It seems soooo bright for my little tent, so I took it out. I don’t understand any of the technical stuff like moL/ppf/dli etc. I didn’t think it was going to be so complicated (for me anyway)
I just want to know the correct LED wattage for my tent to grow a caouple of plants, from start to harvest. Is the SF1000 ok?

Help
Thanks

ps - I did do some searches on this forum but came across some of the issues I mentioned above which is why I’m asking specifically about my situation. Thx
 
coreywebster

coreywebster

Well-Known Member
Basically with modern white LEDs such as the one you have 30w per square foot is good for flowering. Half that for vegging
You have 4 square feet.

25w per square foot will suffice.
Some people like to push harder too.


What will help you is keeping generally higher temperature , like 80-84f . Because the LED doesn't emit much radiant heat.
 
M

Mintaka3

Member
coreywebster said:
Basically with modern white LEDs such as the one you have 30w per square foot is good for flowering. Half that for vegging
You have 4 square feet.

25w per square foot will suffice.
Some people like to push harder too.


What will help you is keeping generally higher temperature , like 80-84f . Because the LED doesn't emit much radiant heat.
Click to expand...
 
Greengrouch

Greengrouch

Well-Known Member
Useful for picking appropriate lighting for space
www.cocoforcannabis.com

Grow Light Calculator - Coco For Cannabis

Our grow light calculator provides an accurate way to analyze & compare grow light fixtures. Enter your own grow light data or select preloaded fixtures.
www.cocoforcannabis.com www.cocoforcannabis.com

I have a little 2x2 seedling tent with a viparspectra v1000 in it, it’s 90w variable dimming at 12” hang height and 100% it reads as adequate for flowering. Not bad for a $50 light, i flipped my 5x5 to 12/12 with the big mars bar light (fce 6500) a week ago and I’ve only got it at 60% rn.
 
TCH

TCH

Well-Known Member
Mintaka3 said:
Hi everyone
I’m new to this forum and I really need help. I’ve been growing for several years under a 300w cfl. Like most people, I now want to change to LEDs but the advice on wattage for LEDs is very confusing,
My tent is small 2x2x4 and many places are recommending lights such as SF1000 which even Spider Farmer promote as being the one for my size tent. As do many other companies… Vipraspectra P1000, Marshydro TS1000 etc. but then I see references saying lights that are 400 or 600 are best and that 1000 is way to strong. Also I found a table that listed 200w for a 2x2 tent
I had actually bought the SF1000 but now I’m wondering if I did the right thing. It seems soooo bright for my little tent, so I took it out. I don’t understand any of the technical stuff like moL/ppf/dli etc. I didn’t think it was going to be so complicated (for me anyway)
I just want to know the correct LED wattage for my tent to grow a caouple of plants, from start to harvest. Is the SF1000 ok?

Help
Thanks

ps - I did do some searches on this forum but came across some of the issues I mentioned above which is why I’m asking specifically about my situation. Thx
Click to expand...
Keep in mind that all those "1000" leds are 100w leds. Marketing scheme. 100-150w will do ya alright in the 2x2.
 
M

Mintaka3

Member
Hi Corey
Thanks for your reply.
Can I just make sure I understand… at 30w/sqft I would be looking at 120w. The SF1000 spec says it’s wattage is 100, so essentially this light would be ok for flowering, right? Sorry to sound so dumb.
As my current grow is only just starting I should therefore use a lower wattage around 50/60w.
I think I was getting confused because sometimes the wattage is actual (old school measure) and sometimes it’s in led wattage.
The tent ranges between 78 and 82*f so I think I’m ok on temperature but I do keep a close eye on it.
 
Last edited:
M

Mintaka3

Member
Greengrouch said:
Useful for picking appropriate lighting for space
www.cocoforcannabis.com

Grow Light Calculator - Coco For Cannabis

Our grow light calculator provides an accurate way to analyze & compare grow light fixtures. Enter your own grow light data or select preloaded fixtures.
www.cocoforcannabis.com www.cocoforcannabis.com

I have a little 2x2 seedling tent with a viparspectra v1000 in it, it’s 90w variable dimming at 12” hang height and 100% it reads as adequate for flowering. Not bad for a $50 light, i flipped my 5x5 to 12/12 with the big mars bar light (fce 6500) a week ago and I’ve only got it at 60% rn.
Click to expand...
Greengrouch said:
Useful for picking appropriate lighting for space
www.cocoforcannabis.com

Grow Light Calculator - Coco For Cannabis

Our grow light calculator provides an accurate way to analyze & compare grow light fixtures. Enter your own grow light data or select preloaded fixtures.
www.cocoforcannabis.com www.cocoforcannabis.com

I have a little 2x2 seedling tent with a viparspectra v1000 in it, it’s 90w variable dimming at 12” hang height and 100% it reads as adequate for flowering. Not bad for a $50 light, i flipped my 5x5 to 12/12 with the big mars bar light (fce 6500) a week ago and I’ve only got it at 60% rn.
Click to expand...
Thanks for the link, I think I need to go through some of those tutorials and educate myself on the led info.
 
Tolerance Break

Tolerance Break

Well-Known Member
coreywebster said:
Basically with modern white LEDs such as the one you have 30w per square foot is good for flowering. Half that for vegging
You have 4 square feet.

25w per square foot will suffice.
Some people like to push harder too.


What will help you is keeping generally higher temperature , like 80-84f . Because the LED doesn't emit much radiant heat.
Click to expand...
Temp depends on the light strength you're running. Higher temps are good for pushing plants in LED. This is also strain dependent, but I have noticed many plants don't like high heat sub 800 ppfd.
 
coreywebster

coreywebster

Well-Known Member
Mintaka3 said:
Hi Corey
Thanks for your reply.
Can I just make sure I understand… at 30w/sqft I would be looking at 120w. The SF1000 spec says it’s wattage is 100, so essentially this light would be ok for flowering, right? Sorry to sound so dumb.
As my current grow is only just starting I should therefore use a lower wattage around 50/60w.
I think I was getting confused because sometimes the wattage is actual (old school measure) and sometimes it’s in led wattage.
The tent ranges between 78 and 82*f so I think I’m ok on temperature but I do keep a close eye on it.
Click to expand...
There is only actual wattage.
That's what you want to look at.

Anything else is marketing nonsense by companies that should be avoided .
 
lizzit

lizzit

Well-Known Member
Sorry to chime in but download a lux meter for your phone. Look for a lux reading of over 30k at top of canopy. Ideally you want canopy to be around 60k as every inch in distance from led you drastically drop in lux. So if your canopy reads 60k lux then 3" down may be 40k or even less. Watts don't mean anything anymore except how much your paying every month.
 
Last edited:
M

Mintaka3

Member
coreywebster said:
There is only actual wattage.
That's what you want to look at.

Anything else is marketing nonsense by companies that should be avoided .
Click to expand...
Ah right, duly noted, the wool has been lifted from this old lady’s eyes! . Now the whole LED thing is starting to make sense. I just figured all those numbers where just another “inches to centimetres” type change.
 
G

GreenRat

Active Member
Mintaka3 said:
Hi everyone
I’m new to this forum and I really need help. I’ve been growing for several years under a 300w cfl. Like most people, I now want to change to LEDs but the advice on wattage for LEDs is very confusing,
My tent is small 2x2x4 and many places are recommending lights such as SF1000 which even Spider Farmer promote as being the one for my size tent. As do many other companies… Vipraspectra P1000, Marshydro TS1000 etc. but then I see references saying lights that are 400 or 600 are best and that 1000 is way to strong. Also I found a table that listed 200w for a 2x2 tent
I had actually bought the SF1000 but now I’m wondering if I did the right thing. It seems soooo bright for my little tent, so I took it out. I don’t understand any of the technical stuff like moL/ppf/dli etc. I didn’t think it was going to be so complicated (for me anyway)
I just want to know the correct LED wattage for my tent to grow a caouple of plants, from start to harvest. Is the SF1000 ok?

Help
Thanks

ps - I did do some searches on this forum but came across some of the issues I mentioned above which is why I’m asking specifically about my situation. Thx
Click to expand...
Spider Farmer 110W is recommended for a 2x2 tent as a basic light for flowering. Depending on whether you want to save electricity or have better yields - you can choose a weaker or stronger light. I have always used 110W at 2x2, but now I bought a 2x4x6 tent, which is like two 2x2 tents. And I bought three Spider Farmer 110W lamps to have a stronger light. You can install 200W if you don't care about saving energy.
Two SF1000 lamps or one SF2000 will not fit into your tent. If you want a stronger light than SF 110W - you need to find a different lamp.

It would make no sense, for example, if you bought a 150W LED lamp, which shines the same as SF1000 110W.
If you want a stronger light than the SF1000, having more Watt, it must be a lamp of similar quality. SF1000 is a very good lamp, some lights of other companies achieve the same result, but downloading 150W. So beware.
 
Daino

Daino

Well-Known Member
lizzit said:
Sorry to chime in but download a lux meter for your phone. Look for a lux reading of over 30k at top of canopy. Ideally you want canopy to be around 60k as every inch in distance from led you drastically drop in lux. So if your canopy reads 60k lux then 3" down may be 40k or even less. Watts don't mean anything anymore except how much your paying every month.
Click to expand...
Or you could download the photone ppfd meter and save yourself looking at lux when ppfd is where you need your head to be at :) start out making the right decisions and a positive attitude and the rest will fall into place
 
Daino

Daino

Well-Known Member
lizzit said:
Sorry to chime in but download a lux meter for your phone. Look for a lux reading of over 30k at top of canopy. Ideally you want canopy to be around 60k as every inch in distance from led you drastically drop in lux. So if your canopy reads 60k lux then 3" down may be 40k or even less. Watts don't mean anything anymore except how much your paying every month.
Click to expand...
Watts mean a lot when you consider using a 200w versus a 720w bro like that's when makes the ppfd a 720w will and should have 1700-1900 ppfd, lux has no place for measuring par without having to do a shit load of boring converting if your plants needs a certain par for every stage to give the plant optimum growth then start there no point starting with lux so wattage is quiet important as higher wattage means higher ppfd allowing one to push those colas into turbo mode with an intensity much like like that big orange ball in the sky so ditch the lux meter and get the right app from the word go too confusing measuring irrelevant things keep it simple and happy growing bro
 
G

Grower1974

Member
This Green Gelato auto grew on a table with a VS4000 @ 50% (198W). 350-450PPFD during veg, and 750-875PPFD during flower.
2 gallon pot. It’s 39” tall and I expect 7-9oz dried from it.

Knowing/using PPFD values almost makes wattage recommendations useless with the efficiency of the 301B/H diodes used in decent lighting over the past 3-4 years.

2nd picture. My 4X4’ tent running the bar light at 75% (385W)(700-925PPFD) with 5 plants in it. Hoping for 20-24oz dried.
 

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Daino

Daino

Well-Known Member
Grower1974 said:
This Green Gelato auto grew on a table with a VS4000 @ 50% (198W). 350-450PPFD during veg, and 750-875PPFD during flower.
2 gallon pot. It’s 39” tall and I expect 7-9oz dried from it.

Knowing/using PPFD values almost makes wattage recommendations useless with the efficiency of the 301B/H diodes used in decent lighting over the past 3-4 years.

2nd picture. My 4X4’ tent running the bar light at 75% (385W)(700-925PPFD) with 5 plants in it. Hoping for 20-24oz dried.
Click to expand...
Are the buds dense or airy they look pretty airy but may just be the pic
 
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