PAR level for seedlings? @300?

.Smoke

Well-Known Member
Seed in bucket with dome= 10,000 lux.
Seedling uncovered 1 day after leaves pop= 35,000-50,000 lux.
Works 99.9% of the time.
20201229_224308.jpg
Forget the $$$ PAR meter....watch the video and spend $30.
It works.
 
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kingromano

Well-Known Member
The sun is apparently between 900/1500 par depending on variables so to say seedlings etc only needs 300 or whatever clearly is wrong as the sun's par is never that low yet cannabis constantly grows fine.
is your sun delivering 900/1500 micro moles 18 hours per day ?
no
thats why we talk about DLI for natural light
 
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kingromano

Well-Known Member
I also work with the cheap lux meter.
then i do the conversion from lux to ppfd

for hps the factor is around 80
so if you want 100micro moles, you need to read 8000lux on your meter

plants can tolerate high ppfd values but the key is to give it progressivly

it's called light acclimatation

start at 50 micromoles for clones and increase it until the end


johnny your plants are cool but keep in mind your never want the plants to yellow
you must keep them healthy green until the end

.smoke, if i may, this plant is getting too much light
it's the perfect exemple of light stress in veg
just turn on one lamp on 2 at this stage

your plant shoud be praying hard all the time with healthy green new growth
nice setup though
 

jonnynobody

Well-Known Member
johnny your plants are cool but keep in mind your never want the plants to yellow
you must keep them healthy green until the end
Day 69 of flower sir. I'd have been lost without your advice. Thanks for getting me back on track :)

.smoke, if i may, this plant is getting too much light
it's the perfect exemple of light stress in veg
just turn on one lamp on 2 at this stage
I'm sure @.Smoke can speak for himself, but I've followed his journal. He certainly does not need your advice, but I'm sure he'll have a good laugh at your expense when he sees your post.

You'll have to forgive me if I laugh a little at the idea of another grower who can't identify a ripe flower giving me advice on "yellowing leaves." Keep up the good work sir. You're amazing.
 
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Nwtexan

Well-Known Member
from what I gathered the general numbers are those
-seedling 60/100 umoles
-veg 300/500 umoles
-flower 800/1000
-flower+CO2 around 800/100ppm up to 1500 umoles
more that is not useful to the plant, since the light provided energy can be used and stored up to a certain point.

even after u set ambient temperatures of 30c+ where the cinetic energy of ambient pump plant phytoreactions to the top levels archivable its wasted money in my point of view to supplement more than those levels of energy.

I get my umoles (more or less) from the spec sheet of my 308 lm301b pcb
having a scheme of what umoles I get on a certain amperage
i have the rough estimate
worse thing was that almost every spec sheets has a total umoles emitted value tested in a sphere so not exatly the same output would get to the canopy....
had to dive deep in to inverse square law to have a realistic estimate of my canopy esposition!!

sadly couldn't afford a real par reader...what brand did u get?
I don't know how real this is, but it's what I got. It seems to read similar to what the graphs for my lights show.
 

Nwtexan

Well-Known Member
Man. The thing i get is that there are a lot of ways to do this and some very strong opinions on what is right.
I think the par meter is helpful and I learned quite a bit reading studies of Cannabis and how it reacts to different PAR levels.

I'm totally green on doing it this way but i've got my seedlings around 180-200. I'll keep an eye out for any light stress and such and try to learn as I do it. I do know that the plant is pretty hardy. The thing i am interested in is that I can tweak some parameters to help the plant grow quicker and stronger. I am not a professional. My grow is small, just a few plants, and I will be experimenting with the dynamics I can control to gett better.

i appreciate the info and help.
 

Nwtexan

Well-Known Member
I tried out my old 400W halide. The reflector could stand to be replaced, but I wanted to see how it did,
Pretty cool. Ive been having to run a wall heater to keep the ambient grow temp in the mid 70's with the LED. With the halide, I'm able to turn the heater down enough just to keep temps in the 60's during night cycle. It's surprising how much less light the halide puts out! I'm getting around 150 UMOL where i have it hung, which is about 18" or so from the plants. Definitely crazy how much light the LED's put out. The halide is good for the colder NW winter. I will use it(switch to my HPS bulb) for a while and if I like it enough will get a new reflector.

It's all a cool experiment at this point.
 

Nwtexan

Well-Known Member
And back to the LED. The Halide was getting the tent into the high 80's, even with the exhaust fan on high. I'm gonna get a new reflector for it and try it again in flower.
 
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