Help using two leds in one tent

[Northeastern]

Ok so I’m having a problem in my tent with light stress. I know I should be able to put my two Mars hydro Tsw 2000 at 50% at 24” but they don’t want that much light. So far the most they can handle is 30%. So my question is if I’m using two lights am I supposed to add the percentage together? Is 25% on both lights pretty much 50% if I only had one light? I’m sorry I don’t have a light meter.

 

[SnidleyBluntash]

Maybe your other parameters are not allowing the plants to use the light. Like temperature and humidity and nutrients. Tell us about that. How old are the plants..?

 

[Tracker]

Ok so I’m having a problem in my tent with light stress. I know I should be able to put my two Mars hydro Tsw 2000 at 50% at 24” but they don’t want that much light. So far the most they can handle is 30%. So my question is if I’m using two lights am I supposed to add the percentage together? Is 25% on both lights pretty much 50% if I only had one light? I’m sorry I don’t have a light meter.

Summing the percentages on the knobs doesn't really give you an idea of the intensity of light on the canopy. What stage of growth are you in? Seedling, early veg, veg, flower?

I use lux light meter app on my android phone to get a good idea of intensity on my canopy. It's not the best like a true PAR meter, but I find it helpful...and it's free.

 

[Northeastern]

Maybe your other parameters are not allowing the plants to use the light. Like temperature and humidity and nutrients. Tell us about that. How old are the plants..?

I don’t think so I got the tent to 70 F and 65% rh when I had them at 50% and tips were starting to yellow and taco. Haven’t fed nutrients until today. They are a little over two months old. And they are in ffhf.

 

[Tracker]

I don’t think so I got the tent to 70 F and 65% rh when I had them at 50% and tips were starting to yellow and taco. Haven’t fed nutrients until today. They are a little over two months old. And they are in ffhf.

Can you post pics?

 

[Northeastern]

Summing the percentages on the knobs doesn't really give you an idea of the intensity of light on the canopy. What stage of growth are you in? Seedling, early veg, veg, flower?

I use lux light meter app on my android phone to get a good idea of intensity on my canopy. It's not the best like a true PAR meter, but I find it helpful...and it's free.

I tried on my iPhone it just didn’t work. I’m in late veg

 

[ZuuTeD614]

I tried on my iPhone it just didn’t work. I’m in late veg

Download thr PPFD Meter

 

[Northeastern]

Can you post pics?

They are doing better since I lowered the %. They look fine until it gets to the last 4 hours of the light schedule then that’s when they fold like a taco.

 

[Northeastern]

Download thr PPFD Meter

My app is saying 320 ppfd.

 

[Tracker]

They are doing better since I lowered the %. They look fine until it gets to the last 4 hours of the light schedule then that’s when they fold like a taco.View attachment 4936478

This pic looks healthy. I recommend you try out a few different light meter apps on your phone to see if one gives useful numbers.

On the lux light meter app, which outputs values in lux. I do about 6000lux in clone, raising up to 12000 day by day in early veg, then raising up to 30000 in full veg, and up to a max of 50000 in flower. Some of my varieties like 50000, some don't like above 45000.

I know I have LEDs that are like 3500k 80cri. Web search for lux to ppfd converter and enter those parameters. It tells you ppfd on that basis. The ppfd numbers I get agree with suggested values for those growth stages.

 

[ZuuTeD614]

My app is saying 320 ppfd.

Well that's no where near enough ppfd I have 414 watts of LED in my 2x4 tent about 18 to 20 inches away. My ppfd is about 1200 and my lux is 51,000.

 

[Roger A. Shrubber]

I don’t think so I got the tent to 70 F and 65% rh when I had them at 50% and tips were starting to yellow and taco. Haven’t fed nutrients until today. They are a little over two months old. And they are in ffhf.

70 is cold for leds, you want the temp of the leaf surface to be around 80, ( it varies according to genetics, but is usually between 75-85)
get a laser thermometer and check, if it's low, growth will be less than spectacular.

 

[Tracker]

70 is cold for leds, you want the temp of the leaf surface to be around 80, ( it varies according to genetics, but is usually between 75-85)
get a laser thermometer and check, if it's low, growth will be less than spectacular.

On my LED plants, I try to keep the air temp between 80F to 85F.

 

[Northeastern]

I had it at 70% rh and 79-83 F and that’s when it stared to happen. So I lowered the temp and rh and it was still happening. The leaves wouldn’t pray they would droop and fold. When I lowered the % they all seemed like they were praying and actually wanted light.

 

[ZuuTeD614]

On my LED plants, I try to keep the air temp between 80F to 85F.

Yup my LEDs I don't go under 80° my average around 82-83. And this is my lux and and PPFD. And my plants love it.

 

[Northeastern]

Yup my LEDs I don't go under 80° my average around 82-83. And this is my lux and and PPFD. And my plants love it.

Someone said it’s because I didn’t raise the % slowly from seedling stage. Could that be the reason?

 

[ZuuTeD614]

Someone said it’s because I didn’t raise the % slowly from seedling stage. Could that be the reason?

I'm not to sure about that, seems right though. Always start low and gradually raise the percent as the plant grows.

 

[Roger A. Shrubber]

I had it at 70% rh and 79-83 F and that’s when it stared to happen. So I lowered the temp and rh and it was still happening. The leaves wouldn’t pray they would droop and fold. When I lowered the % they all seemed like they were praying and actually wanted light.

70 rh is too high, they won't drink a lot if the humidity is that high. try to get it down around 50-55%, they'll drink more, which makes them grow faster, and they'll transpire more, which helps them cool off on their own

 

[Tracker]

Someone said it’s because I didn’t raise the % slowly from seedling stage. Could that be the reason?

If your increase intensity, go little by little each day. If you crank it up quickly, the plants will stress.

 

[Roger A. Shrubber]

Someone said it’s because I didn’t raise the % slowly from seedling stage. Could that be the reason?

not sure if thats the only reason, but it probably contributed a little, it's always good to let them adjust a little at first. when i put a plant into flower, i will set them under the canopy of a larger plant (i run a perpetual) for a couple of days till they get used to the more intense light