Quantum board not working properly

RamenB

Member
Hello i bought quantum board From this
Alibaba seller And that exact type. But it has been performing poorly. First try was from seedlings that had started out in a pot out in a window getting sunlight for the start and then soon as i put them in a tent, i could notice hust within hours that the leaves started to hang and maybe a day later the leaves would get much lighter in colour. And they died eventually. Second time i tried from seedlings under the quantum board from the start, they did pop up from the soil but same thing started happening so i changed to a 125w fluorescent 5000k and they got better and started to grow. But now since they have grown for ca 4weeks, and they are not big cause the quantum board slowed the growing process im guessing. I decided to put the quantum board up again but same thing happens. I leaning on that my quantum board is a fake one with not real samsung lm301h diodes? Any ideas.
 

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Rocket Soul

Well-Known Member
Hello i bought quantum board From this
Alibaba seller And that exact type. But it has been performing poorly. First try was from seedlings that had started out in a pot out in a window getting sunlight for the start and then soon as i put them in a tent, i could notice hust within hours that the leaves started to hang and maybe a day later the leaves would get much lighter in colour. And they died eventually. Second time i tried from seedlings under the quantum board from the start, they did pop up from the soil but same thing started happening so i changed to a 125w fluorescent 5000k and they got better and started to grow. But now since they have grown for ca 4weeks, and they are not big cause the quantum board slowed the growing process im guessing. I decided to put the quantum board up again but same thing happens. I leaning on that my quantum board is a fake one with not real samsung lm301h diodes? Any ideas.
What environment (temps/rh) and what intensity and what height? Of course you can burn the plant and mess it up with too much light. This has grower error written all over it.

But dont worry its not a dodgy light.
 

Pparker88

Well-Known Member
Yeah,
It's definitely the incorrect diodes that are causing them not to grow.
Wrong brand name....


Wow... :wall:
i'm happy i went with HLG QBs. built my own...it was easy and the lights kick ass. i almost ordered from Alibaba
 

RamenB

Member
I had it on full “power” at ca 60 cm away from the plants that are in the attachment. The temp is around 22c to 27c. I have a small tent 60x60x140cm . I have tried adjusting the height but i do lower the potentiometer When i had them closer ca 30cm away
 

RamenB

Member
What environment (temps/rh) and what intensity and what height? Of course you can burn the plant and mess it up with too much light. This has grower error written all over it.

But dont worry its not a dodgy light.
Yeah i did have them to close at full power for the first time that definitely killed them, but now i had them ca 60cm away and it still happened
 

coreywebster

Well-Known Member
100w of 301h in a 2x2 is fine for flowering @14-18" away.
50% power for veg, considerably less for starting seeds.

They are far too intense

27c should be the minimum lights on temp.

You need to make sure your RH is on point for VPD at 27degrees C .

Don't underestimate the light output in comparison to cfm, metal halide ect.
 
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RamenB

Member
100w of 301h in a 2x2 is fine for flowering @14-18" away.
50% power for veg, less for starting seeds.

They are far too intense

27c should be the minimum lights on temp.

You need to make sure your RH is on point for VPD at 27degrees C .

Don't underestimate the light output in comparison to cfm, metal halide ect.
Ok im not familiar with these terms, Have to look it up.
 

coreywebster

Well-Known Member
Ok im not familiar with these terms, Have to look it up.
Google LED VPD chart.
It will tell you what relative humidity is best for 27degrees c to give the best transpiration so the plant can uptake water and nutrients without major stress.
 
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coreywebster

Well-Known Member

RamenB

Member
Ok so im guessing the air is to dry my temp/humidity meter says 26c/36% , thanks for the links will have a closer look
 

RamenB

Member
Im gonna change the lamp back tomorrow and try to keep the humidity higher,, for now im using the 125w fluorescent bulb and they seem to be recovering also the humidity is higher, sprayed some water on them and i put some water in a glass hoping that will help
 

coreywebster

Well-Known Member
Im gonna change the lamp back tomorrow and try to keep the humidity higher,, for now im using the 125w fluorescent bulb and they seem to be recovering also the humidity is higher, sprayed some water on them and i put some water in a glass hoping that will help
A humidifier would be useful if your natural humidity is low.
But a bowl of water with a small towel hanging over the side acting as a wick with a fan blowing on the towel will help a bit.

Issue you have is too low humidity causing high VPD with a plant that has little to no root or leaf mass to be able to transpire enough to keep up, its compounded by having a light that's very powerful.
Nothing wrong with fluorescent for starting seeds. You wouldn't chuck a baby on a treadmill.
 

HydroKid239

Well-Known Member
Google LED VPD chart.
It will tell you what relative humidity is best for 27degrees c to give the best transpiration so the plant can uptake water and nutrients without major stress.
Thanks for that. I'm still on my 1st grow/1st set of clones and I've heard someone mention VPD. Never checked up on it til now. I have a question tho.. I seen where my Temp and RH lined up and it's on the nose. I'm at 40-45% RH @ 77-79F Temp.. and i'm in mid-late flower. So.. the question is.. do I try to keep my levels in that purple range as I go along?
 

RamenB

Member
So Im getting a humidifier cause im not able to keep it stable. Its rocking from 60-80% im spraying the plants with water and im put some wet paper towels on the pots hanging. The other plant seem to be doing better then the other
 

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