By continuing to use the website or clicking Accept you consent to our cookies and personal data policy. For details please see Privacy Policy
Accept
PAR/PPFD and light height
GreenHillZonestarted grow question 4 years ago
PAR/PPFD: does light height matter if your PPFD is in the right range? Another way to ask: is 300 PPFD @ 2 feet the same as 300 PPFD @ 20 feet, or are there other factors involved? (assuming heat, C02, all other non light inputs equal)
Solved
Setup. Lighting
like
The8thChevronanswered grow question 4 years ago
For the most part, these things are equal whether they are 2 inches or 2 feet. You want to go by ppfd.
Things that DO change with height? Penetration will decrease as the light is moved further away. Coverage area will decrease as the light is moved closer. Generally, I try to keep my light at maximum power and have the correct PAR.
Ppfd:
Seedlings 400
Veg 600
Bloom 900
You can increase ppfd if you use CO2.
GrowCNanswered grow question 4 years ago
I set my light height and power based on PPFD. When plants are young and smaller I will lower the light and adjust the power to match what the plant needs. Then when flowering and I want light bouncing off the walls of the tent for the side and bottom leaves I raise the light to a high position and crank up the power. I also get more even lighting throughout my tent when the light is higher with the power turned up.
2 likes
Complain
Similar Grow Questions
Solved
Fizwig
Enlighten me (Grow light advice)Hey fellow growers,
I'm revamping my grow room and need a new 300W LED light. I'm looking for the best possible light output without breaking the bank on electricity. Any recommendations for energy-efficient, high-performance lights in 2024? Your expertise is greatly appreciatedSetup. Lighting
2 months ago
1
Solved
OnlyAutos
experienced growers are in demandšµāš«š”Hey volks š I'm trying to grow 3 different grow phases in my 4x4 tent, but getting too much problems with my light.(Mars Hydro TSW 2000) its too strong for my little plants. Can you give me same advice about hight/intensity?
Thanks alot and happy growingš±Leaves. Tips - Burnt
Setup. Lighting
2 months ago
2
3
Solved
GeminiCQC
Help with issues IDI have a photoperiod in a 5 gal using BAS light. It is currently day 3 of week 4 , and I'm getting some damage on the tops. Would this be light stress or another issue? The tips are starting to go light green. Using the 200 watt light for the 2x4x8 ac infinity tent.
Leaves. Tips - Burnt
Setup. Strains - Photoperiod
Setup. Lighting
3 months ago
2
2
Solved
L8bloomr1008
Do you lower light intensity and temps towards the end of flower?So Iām in mid flower, start of week 7 to be exact. Iām curious on when you guys start pulling back light intensity and going with a little cooler temps. Iām running a 240W S33 from AC infinity in a 3x3.
Should I be going strictly off of PAR or VPD at this point.Setup. Lighting
3 months ago
1
3
Solved
Blubbiblubb
How to manage a tall plant with a thick stem in week 1 of flowering?One plant I ordered online was pre-grown. Now, itās about 20 cm taller than my other plants. At the top, the taller plant gets more than 1000 PPFD, while the lower canopy gets about 500 PPFD. Itās currently week 1 of flowering. The stem is too thick to bend down.What would youdo?
Plant. Too tall
Setup. Lighting
a month ago
5
7
Solved
leo__bulero
How many plants in a 70x70x160cm tent with 100W?Hello, I have a grow tent kit 2x2 with a 100W 301H EVO Spider Farmer light. I have put there three 11L pots. But now I realize the size/light of my tent might not be enough. Could I manage by adding an additional 60W lamp you reckon or is it best to discard at least 1 plant? Thx
Setup. Lighting
a month ago
2
1
Solved
Smoth313
Leafes curl upHey das sind meine Autos anfang Tag 6.Die blƤtter wƶlben sich leicht nach oben ist das normal/okay? oder ist das Lichtstress? Lampe ist eine AC Infinity Evo 4 300 watt hatte ich seit Tag auf 40% laufen und habe dann nach Tag 3 auf 30% reduziert. abstand habe ich 45cm.
Leaves. Curl up
Setup. Lighting
a month ago
4
3
Solved
eppeep42
Height Difference when growing different strains in one tentIm afraid my Gorilla will outgrow the Lemon Cherry significantly in height, will that be a big problem? or will the lemon cherry maybe catch up a bit in full flower so the difference in light intensity wont be that big? both same age. Spiderfarmer SF-1000 (2024 Version)
2 months ago
5
4
Solved
Chucky324
New UV Supplemental Light BarsHello. I looking for someone with experience with the supplemental light bars. Is there any tips or tricks with these lights. How's your experience been with them? Anything else I need to know about them? Do they work like advertized?
Setup. Lighting
2 months ago
3
4
Solved
Frezzy
GrowlampeHallo an alle,
Ich bin schon lƤnger auf der Suche nach einer guten Growlampe die auch mehrere Pflanzen ohne Probleme hochziehen kƶnnte. Habe schon vieles gutes Ć¼ber die Mars Hydro TS600 gehƶrt ist die Lampe besser fĆ¼r einzelne Pflanzen oder kann man auch mehrere hochziehen?Setup. Lighting
6 days ago
3
3
Solved
Sheldor
Hight ProblemsIāve got 3 plants in my tent, but theyāre all different heights. To compensate, Iāve hung my light at an angle, so one end is closer to the smaller plants.
My question is: Does this help, or am I better off keeping the light level? Any tips for dealing with uneven plant heights?
12 days ago
2
6
Solved
Chilltkroete
Started the plants off with 60 watts. Increased to 100 watts today with a 20/5 schedule. Could I increase to the full 150 watts already or should I give them a few days with 100? Thanks in advance for any advice. Itās my first indoor grow with this setup and Iām still learning :)
Week 1
Setup. Lighting
15 days ago
1
Solved
HAPPYCHEFF
Vegetative growth poor sunlightHey time grower here. started growing some seeds i found in some weed i had, plants already on soil on the first stage of vegetative growth but on my backyard i only have 8-9 hours of direct sunlight, will this work for a good vegeative growth? i know they need 18h at least :c
Setup. Lighting
19 days ago
2
2
Solved
Bluegrower92
Stretchy seedlings...worried!Hi, I have 5 seedlings on day 7. 2 of them are going fine but the three from ditch passion were very stretchy though. Likely due to having the light to far away. Take a look, any advise would be great. Cheers all!
Setup. Lighting
Setup. Seedling
21 days ago
1
1
Solved
MrShortTermMemory
Lighting cycle for VEG stage. Is 24x7 OK?Hi,
Should I use the VEG lights 24x7 from the time I plant my seed until it's ready to bloom, or would something like 18 hours on and 6 hours off make more sense? Is there a "best practice" for veg lighting? It has worked for my first 3 grows. VIPARSPECTRA 600W LED
Thanks,
Mr.STMSetup. Lighting
8 months ago
7
7
Solved
Green_Man_420
Light intensityMy plants have been looking sad for a couple weeks. Tried everything then the other night I turned my light down to 40% giving a DLI of 28 they perked right up with 24 hours. I have now put it up to 60% giving a DLI off 39 will this be ok or should I keep it low. Week 2 flower.
Setup. Lighting
8 months ago
1
2
Solved
hweixd
Got a Mars Hydro TS600, will it do alright?My plan is to grow only 1 plant, in a 40x40x120 tent. I know the tent is pretty small but hopefully i can do some training on the plant to grow wide
Will the light do until the end? 100wats, but no light dim possibility. Currently growing seedling at 13 dli at 60 cm
Setup. Lighting
9 months ago
2
1
Solved
Lew420
Bad idea?Will a mars hydro TS1000 be too strong for a 60x60x140cm tent?
I have been using a TS600 and TS1000 in tandem in a tent 4x too big for the light level, I have been growing strong and tasty buds but with low yields so downsizing my tent size to maximise the light.Other. General questions
Setup. Lighting
9 months ago
3
3