Seedlings and a new quantum board

[TheTinkerer]

I have a fresh new quantum board that I want to put over my seedlings in a 2x2 cabinet. It’s a single 288v2 with an “a” type driver. My plants are a week old and they’re currently about two inches below a 105w cfl.
What height and power do you recommend when I swap the lights?

 

[mathewscott]

Good ?

 

[callies]

I have a fresh new quantum board that I want to put over my seedlings in a 2x2 cabinet. It’s a single 288v2 with an “a” type driver. My plants are a week old and they’re currently about two inches below a 105w cfl.
What height and power do you recommend when I swap the lights?

how much head room do you have. no expert and i haven't used a QB yet i do use leds but put it half way to 100W @ 12inchs should be fine or 18 inch id probably leave the board half power the entire veg then crank it for flower. any closer then 12 inches you'll start bleaching the plant. just my two cents
is the 288v2 a 300w two panel board

 

[Rocket Soul]

Start it as high as you can and then start lowering slowly.

 

[callies]

Start it as high as you can and then start lowering slowly.

i still say dim the light and keep it closer unless you dont care for saving power

 

[TheTinkerer]

I have sing

how much head room do you have. no expert and i haven't used a QB yet i do use leds but put it half way to 100W @ 12inchs should be fine or 18 inch id probably leave the board half power the entire veg then crank it for flower. any closer then 12 inches you'll start bleaching the plant. just my two cents
is the 288v2 a 300w two panel board

I have a single 288v2 QB 135w max rated.

 

[TheTinkerer]

Start it as high as you can and then start lowering slowly.

Lower it slowly…
How far? Then what?

 

[TheTinkerer]

So, dim it to 50 percent, hang it 18 above plants and lower it an inch a day until I get to 12 inches above plants or I see bleaching?
Sound good?

 

[Rocket Soul]

Basicly, bring in light slowly, looking out for purple stems and mag deficiency, or general signs for the plant not being happy.

 

[callies]

I have sing

I have a single 288v2 QB 135w max rated.

oh just leave it 18 inch for the entire grow adjust it as the plant grows. nothing more too it easy as pie

 

[Dave455]

I have a fresh new quantum board that I want to put over my seedlings in a 2x2 cabinet. It’s a single 288v2 with an “a” type driver. My plants are a week old and they’re currently about two inches below a 105w cfl.
What height and power do you recommend when I swap the lights?

15k to 20k lux reading......

 

[weemandime3]

Basicly, bring in light slowly, looking out for purple stems and mag deficiency, or general signs for the plant not being happy.

So I have a mag def if I have purpling stems? Because of the led light being too close? I thought that was aeration related, and I’m really confused,lol.

 

[Rocket Soul]

I cant say im hundred percent on all the whys and what nots but here goes: no, mag def is usually a light green clorosis, or the leaf beween "veins" going very light green. Not to be confused with iron def clorosis which is more yellow like. Purple stems is a more general, not happy plant sign. As led lights are very intense and dont promote the same transpiration as for ex hps its very easy to give too much light with the plant having too little absorbed nutes and water to handle the light. The result is light bleaching, general deficiencies most often C and or Mag and purple stems.

 

[TheTinkerer]

Update-
My seedings are looking very happy and my qb288v2 is only using 26 watts!
It’s a single board qb288v2 4000k with an hlg-120h-54a driver. The driver has been turned down all the way since I put it on the seedlings about a week ago. Today I got a kill-a-Watt and it says my light was using 26 watts at the lowest setting. I turned it up to max and it reads 162 watts. I had thought that with this driver I could only dim to 60 percent, so I was surprised to see that I was only using 26 watts. Again, the seedlings are happy, no stretch at all. I did turn it up to 27 watts and you can see the difference in brightness. Oh, and there is 14” between my board and my plants, but the plants are under a plastic dome.

 

[18touring]

Recommended PPFD for a seedling is about 100-300. Easy way to calculate roughly what you are putting out with that light is it to take the μmoles and multiply it by wattage. This will give you a pretty good idea of what wattage you need to run to get the max results...I believe those boards are somewhere around 2.53μmoles.

2.53μmoles x 26 watts = 65.78 PPFD @ 18"

Since the light is closer yourPPFD will be higher then that obviously. But you can use that calculation during and grow stage depending on Veg or Flower to see where your at. Hope that helps.

 

[TheTinkerer]

Recommended PPFD for a seedling is about 100-300. Easy way to calculate roughly what you are putting out with that light is it to take the μmoles and multiply it by wattage. This will give you a pretty good idea of what wattage you need to run to get the max results...I believe those boards are somewhere around 2.53μmoles.

2.53μmoles x 26 watts = 65.78 PPFD @ 18"

Since the light is closer yourPPFD will be higher then that obviously. But you can use that calculation during and grow stage depending on Veg or Flower to see where your at. Hope that helps.

Thanks.
Using that technique, what PPFD will I be shooting for during early veg, late veg, early bloom, etc…?

 

[18touring]

Thanks.
Using that technique, what PPFD will I be shooting for during early veg, late veg, early bloom, etc…?

Honestly that is a loaded question because there are so many variables... Strain, Genetics, etc. A simple answer would be start slow and ramp up watching for any stress or light burn. Your leaves and plant will let you know. Personally I aim for 300-600 in veg (early to late) and in bloom 600-950 (early to late).

I recommend making small adjustment everyday until you hit your target so you can watch the progress of your plant and make sure you are not hitting it with too much light too fast. These lights are fantastic and can really give the plant a good light bath. With your light there isn't too much harm you can do at all, so have fun and experiment.