Lower Lights or use the dimmer?

S

ShawnSunshine

Well-Known Member
Currently my grow lights are at 24 in for my seedlings and I'm running the lights at about 25% Power.

I currently get 300 umol/par on the center plant and the others get 215.

I have a Maglong Full Spectrum 2000w equivalent (220 Watt draw)

According to the manufacturer it is better just to simply I'll keep the lights at 24 inches and increased the intensity as the plant grows.

I like to know from you all if it's necessary to move the lights?

Aside from the fact that honestly the plants will grow and I will need to maintain that 24 in.

But is there a reason to get closer vs dimmer control?

Getting closer would only make the center plant more intense heat as far as I would see and it wouldn't be even across the board like it is now comparatively.

So I just want your thoughts on this.

Thanks.
 
ShawnSunshine said:
Currently my grow lights are at 24 in for my seedlings and I'm running the lights at about 25% Power.

I currently get 300 umol/par on the center plant and the others get 215.

I have a Maglong Full Spectrum 2000w equivalent (220 Watt draw)

According to the manufacturer it is better just to simply I'll keep the lights at 24 inches and increased the intensity as the plant grows.

I like to know from you all if it's necessary to move the lights?

Aside from the fact that honestly the plants will grow and I will need to maintain that 24 in.

But is there a reason to get closer vs dimmer control?

Getting closer would only make the center plant more intense heat as far as I would see and it wouldn't be even across the board like it is now comparatively.

So I just want your thoughts on this.

Thanks.
Click to expand...
I recently had this same kind of debate in my own head over what was better and I decided to use a light meter app on my iPhone and adjust height accordingly to keep it no more than 500 ppfd on the canopy for veg but probably more like 300 to start seedlings and increase as they grow
But I would stick within pretty close range of the manufacturer recommended hanging height and use dimmer as needed to bring up the light intensity as veg progresses and hopefully by flower you’d be ready to crank it up without shocking them or getting light bleaching etc
 
weednerd.anthony.850 said:
I recently had this same kind of debate in my own head over what was better and I decided to use a light meter app on my iPhone and adjust height accordingly to keep it no more than 500 ppfd on the canopy for veg but probably more like 300 to start seedlings and increase as they grow
But I would stick within pretty close range of the manufacturer recommended hanging height and use dimmer as needed to bring up the light intensity as veg progresses and hopefully by flower you’d be ready to crank it up without shocking them or getting light bleaching etc
Click to expand...
Only 500 umol for vegetative huh?



Isn't the the bloom period?

somewhere between the 800 to 1000?

Yeah I have a light meter on my phone as well.

It's a pretty good app for Android and it's pretty close to an actual light meter.
 
Boatguy said:
More depends on the footprint you are looking to cover. If the light covers 3x3 at 24", any closer will shrink that footprint. If you were trying to cover a 4x4 with that same light you would have to do the opposite and run the light less dimmed.
Click to expand...
Yeah I'm looking 10 inch x 42 inch area, in the windowsill but of course I have 5 and 1/2 ft of height to work with.
 
ShawnSunshine said:
Only 500 umol for vegetative huh?



Isn't the the bloom period?

somewhere between the 800 to 1000?

Yeah I have a light meter on my phone as well.

It's a pretty good app for Android and it's pretty close to an actual light meter.
Click to expand...
500 or so works for my seedlings and as they mature I do turn it up right now they are getting 550-600 but if the OP has seedlings I’d rather not recommend too high of ppfd until they get used to it
I use the Photone app and with the little piece of paper over your selfie camera to act as diffuser it is very accurate in my experience
But you are correct the bloom period will require much higher readings close to 1000 if possible
 
weednerd.anthony.850 said:
500 or so works for my seedlings and as they mature I do turn it up right now they are getting 550-600 but if the OP has seedlings I’d rather not recommend too high of ppfd until they get used to it
I use the Photone app and with the little piece of paper over your selfie camera to act as diffuser it is very accurate in my experience
But you are correct the bloom period will require much higher readings close to 1000 if possible
Click to expand...
Oh wow I forgot all about the piece of paper to make it more accurate I remember seeing a video about that too.

Would like a piece of printer paper do?

I hear that most recommendations for seedlings are are 300 umols so that's why I wanted to start there.

It's very possible that my seedlings aren't getting enough energy.

I'm going to post some pictures tomorrow evening.

By that time it will be officially 11 days of growth including germination.
 
Boatguy said:
More depends on the footprint you are looking to cover. If the light covers 3x3 at 24", any closer will shrink that footprint. If you were trying to cover a 4x4 with that same light you would have to do the opposite and run the light less dimmed.
Click to expand...
He's got it correct here.

ShawnSunshine said:
Yeah I'm looking 10 inch x 42 inch area, in the windowsill but of course I have 5 and 1/2 ft of height to work with.
Click to expand...
I use 220w boards like you and have found you start losing footprint once the light is closer than 19" from the canopy.
 
ShawnSunshine said:
Oh wow I forgot all about the piece of paper to make it more accurate I remember seeing a video about that too.

Would like a piece of printer paper do?

I hear that most recommendations for seedlings are are 300 umols so that's why I wanted to start there.

It's very possible that my seedlings aren't getting enough energy.

I'm going to post some pictures tomorrow evening.

By that time it will be officially 11 days of growth including germination.
Click to expand...
A piece of printer paper works perfectly for the diffuser that’s what I use, and yes keep an eye on them if you see them stretching at all I’d increase it bit by bit
But I think you have the right idea around 300 for germination but for veg anywhere from 500 earlier on and then increase as needed to get them ready for flower light intensity
But as stated above desired footprint is a huge factor as well to take into consideration
 
You must log in or register to reply here.

Similar threads

O
Lighting Decisions are haaaard.
Replies
17
Views
2K
Jonesfamily7715
J
rockso15
Reducing LED's power to 50%, but lowering them 50% closer to plants
Replies
9
Views
875
kilostowers
K
U
Grow light question
Replies
16
Views
1K
Uzimanian
U
wakeNbaker46
ES 300 V2 lights - how to use the dimmer correctly?
Replies
1
Views
395
Moflow
Moflow
bignugs68
Lower new leaves that don't get light are blotchy yellow?
Replies
3
Views
347
pegboy
pegboy
Back
Top