Spectrum settings

[Tylerjones]

Hello fellow growers! I'm seeking out for help, yes I've googled what I'm about to ask, nothing comes up. My question is, I have a 1100w led grow light with adjustable spectrums. I am curious of what numbers I should dial this light into to prove a good growth for the veg stage. It is in a 3x3x72" grow tent, temp is around 74°f and humidity is around 55.

 

[threatco]

In vegetative stage you get less stretchy plants with more blue spectrum.

So you could lower the red lights brightness to achieve that.

But you may want to be sure you are getting a healthy amount of total ppfd before you reduce the red any. Arguably, a light heavy on red is better than not enough light.

If you have a newer smartphone you you can use a lux meter app to check how bright the light is at your plants and use the waveform website to roughly translate that to ppfd.

For mid to late vegatative you want about 400 ppfd would be my guesstimate.

Convert Lux to PPFD - Online Calculator | Waveform Lighting

Online calculator to convert illuminance (lux) to PPFD (micromoles per second per meter squared).

www.waveformlighting.com

Lux Light Meter Pro - Apps on Google Play

Measure illumination and light intensity level

play.google.com

 

[Beowuuulf]

good questions and welcome to the farm mate, i think you should have both dialed to 100%, if you have less vertical space you could dial bloom down during veg cycle this will be less reds suppressing stem elongation! if space is not a problem both at 100 will be best results
if you dial down veg and not bloom, you may get longer than usual plant, from what ive read. dialing both down together will dim the unit. with both modes on 100 i recommend setting the light at 25 inches and moving it down 1 inch per day and back off 1 foot if leaves go pale or yellowish

 

[Jimster]

I agree with @Beowuuulf with using both of them. Plants need different spectrums for different processes, but that doesn't mean that it is beneficial to give them less. A lot of factors affect how much a plant stretches, with spectrum being only one factor. Blurple lights work OK, but a well balanced spectrum covers all of the bases. My philosophy is to try to replicte nature as much as possible, at least regarding light and nutrition. Additional reds during flowering is beneficial, but adding blue to the mix seems to boost potency. I think it is more important to have enough light in all of the needed color bands rather than to just try to supply the main ones.

 

[Tylerjones]

Thank you for the replys! I currently have the light set Veg 100% bloom 10-20%. It seems like it's doing ok on the plants, the light is roughly 20 inches from my plants. I'll have to try 100% for both settings on sunday, I want to complete 1 week of the current settings. I'm new to this and from some changes that I've done already put stress on the plants once before, note these plants are 8 weeks old and have had alot of stress. They are my test run plants for when my diesel comes in. These now are dirt weedI'll post a picture of the lights in the setting I have now. Taken at 6:35 am 5-21-20.
I download the app and I will definitely try it out when I get home from work today.
Thank you for the replys and not being smart asses like other sites.

 

[Jimster]

The plants are very small for 8 weeks old. The one plant in the photo looks like it was cooked, but the others look OK but small. At 4 weeks, I usually have roots coming out the bottom of a 5 gallon bucket, so something is slowing down the growth considerably. They look healthy and seem to be getting enough light but just aren't growing like I think that they should. I know the question was regarding the light, but what type of growing medium are you using?

 

[Tylerjones]

I'll give you the run down :) I started with 9 pretty little plants, gave all but 4 away. I started with crap soil 4 weeks in I transplant from a tray to a 4inch pot still with crapy soil. I got excited as a new grower shouldn't do and planted them in a 10 inch pot a week later (stressed plants). Started to test the soils 1.5 weeks later and realized my ph was at 2.
I went to a grow store and bought fox farm ocean soil and 2 gallon fabric pots. Put them in the new soil and pot within 4 days of buying new soil.
Yes I I transplanted way to many times and to soon so no root growth really occurred. I should of never cheaped out at the beginning. I regret it. I know now when my diesel comes in to not be crazy like I did. Now they seem to be doing good.(well better) oh and I over watered the first 5 weeks not knowing better.

 

[Beowuuulf]

hello and good morning,

I worry that giving light at those settings will give the plant not enough light to grow as threatco mentioned but rather just enough to maintain life
if the light. 20 inches to the canopy with the bloom light 10-20% i THINK you need to halve to distance to the plants, so 10 inches?
if both are on 100% 20 inches sounds good

these plants are i would restart. I had some that i rootbound early and they never grew bigger than that while identical plants have exploded in size

 

[threatco]

Thanks for the rundown. These are all very normal learning moments I think most of us went through at one point.

They could do with very low light levels until they recover from the shock and actually show signs of daily growth. Better to give too little light at this moment rather than too much.

 

[Tylerjones]

My ppfd is around 320 threatco, I moved the light down to 12" from the plants as beowuuulf mentioned to lower the lights. And 3 hours later they all was bending closer to the light as the would the sun, I assumed my light height was a little off lol.

Beowuuulf I am restarting as soon as my new seeds come in. Theses seeds was out of some dirt weed, I figured I would trial and error with the free ones first so I didnt waste money on the purchased seeds.

 

[Beowuuulf]

My ppfd is around 320 threatco, I moved the light down to 12" from the plants as beowuuulf mentioned to lower the lights. And 3 hours later they all was bending closer to the light as the would the sun, I assumed my light height was a little off lol.

Beowuuulf I am restarting as soon as my new seeds come in. Theses seeds was out of some dirt weed, I figured I would trial and error with the free ones first so I didnt waste money on the purchased seeds.

Good... these guys could start runnin so we shall keep our fingers crossed

 

[revfunk]

What's the real wattage on your LED my friend???

 

[Tylerjones]

Beowuuulf I'm praying I'm shooting for a atleast a little something off these plants. I expect an oz total out of the four. It's not much but I cant aim high when they've had a rough life

Bubblefunk, the lamp just says 1100watts, and the website description says the same. I'm sure it's not a true 1100w due to it being a cheaper scale light.