Slow growth

Hi guys and girls,

Im back after a year or so of not really growing. I was using 250w hps but in my small space i just couldnt manage the heat anymore so moved on to led, this one to be exact,

VIPARSPECTRA Reflector-Series 300W LED Grow Light Full Spectrum for Indoor Plants Veg and Flower https://www.amazon.co.uk/dp/B01FNVYSYY/ref=cm_sw_r_sms_apap_FJ4msZXF3fjbA

I dont know weather its just how led work or i have bought a dud or what but im on week 3 and my nirvana criticl auto is only a few inches high and only just putting out its second set of leaves, to me it just seems like very slow growth.

Also compared to pictures online my led is a different colour, online leds light up grow space purple, mine is a very light pink almost white, is this right? edit: ok after taking the picture mine is purple too

Currently the light roughly 12" away from the seedling, i have a fan blowing on the seedling and the temp never maxes past 27'c. I started the seed in a rapid rooter plug and then transplanted into a small 4" pot with some light soil and perlite.

Ill post pics tonight after work.

Edit: got my gf to send on some pics

Smiffy2k9 said:

Hi guys and girls,

Im back after a year or so of not really growing. I was using 250w hps but in my small space i just couldnt manage the heat anymore so moved on to led, this one to be exact,

VIPARSPECTRA Reflector-Series 300W LED Grow Light Full Spectrum for Indoor Plants Veg and Flower https://www.amazon.co.uk/dp/B01FNVYSYY/ref=cm_sw_r_sms_apap_FJ4msZXF3fjbA

I dont know weather its just how led work or i have bought a dud or what but im on week 3 and my nirvana criticl auto is only a few inches high and only just putting out its second set of leaves, to me it just seems like very slow growth.

Also compaired to pictures online my led is a differnt colour, online leds light up grow space purple, mine is a very light pink almost white, is this right?

Currently the light roughly 12" away from the seedling, i have a fan blowing on the seedling and the temp never maxes past 27'c. I started the seed in a rapid rooter plug and then transplanted into a small 4" pot with some light soil and perlite.

Ill post pics tonight after work.

Click to expand...

I have a few of those vipar lights that I use for vegetable seed starting, and while they are bright they are definitely not 300w. Closer to around 130-140w iirc.

That said, I did grow a Harlequin plant under one all the way to harvest as an experiment and got 6oz dry from it. So while it won't perform like Cobs or QBs it should still be perfectly usable, especially for a smaller grow. I also didn't notice any particularly slow growth like you describe, in fact it vegged very quickly and healthy.

Sureshot2 said:

I have a few of those vipar lights that I use for vegetable seed starting, and while they are bright they are definitely not 300w. Closer to around 130-140w iirc.

That said, I did grow a Harlequin plant under one all the way to harvest as an experiment and got 6oz dry from it. So while it won't perform like Cobs or QBs it should still be perfectly usable, especially for a smaller grow. I also didn't notice any particularly slow growth like you describe, in fact it vegged very quickly and healthy.

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6oz o.0, that beats anything i've ever harvested, how long veg did you give?

I had a heat issue in the first week, so maybe its recovering from that. I had the light way to close with no air movement in the closet.

but it is a very weak light. I think PAR was like 220 at 18 inches. Mars300 is 315 par at 18 inches, so if that tells ya anything, lol..

InTheValley said:

but it is a very weak light. I think PAR was like 220 at 18 inches. Mars300 is 315 par at 18 inches, so if that tells ya anything, lol..

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i don't know what you mean?

In the grow world, PAR ( Photosynthetic Active Radiation ) which is a measurement of light power between 400nm and 700nm and it is used to give an indication of the power of light present that is used by plants for growth.

So, the lower the PAR number, the lower expectations of growth and development to the plant. Thru what Ive seen and read, and thru trail, 225 PAR is the least for lower end grows. Definitely not a good flower Number for sure. Buy Yourself a LUX meter, and get your canopy at 20,000 LUX and up. For a simple general rule of thumb, 20,000 lux is around 250 PAR, great for seedlings, OK for Veg, crap for flower.

Scrap the plant and start another. an auto looking like that being week 3 it’s a waste to keep it going to be honest. Pop another and wet the soil then wait until the cup you start it in is dry before you water again. Think you overwatered it and drowned it. I would scrap it and start another. You can easily grow a couple oz with that light for one auto. Keep the light start a new one and make sure the soil drys out before you water. Don’t feed until first set of leaves that look like the classic weed leaf. You’ll have much better results. Good luck. Don’t kill it with love and let it grow

InTheValley said:

In the grow world, PAR ( Photosynthetic Active Radiation ) which is a measurement of light power between 400nm and 700nm and it is used to give an indication of the power of light present that is used by plants for growth.

So, the lower the PAR number, the lower expectations of growth and development to the plant. Thru what Ive seen and read, and thru trail, 225 PAR is the least for lower end grows. Definitely not a good flower Number for sure. Buy Yourself a LUX meter, and get your canopy at 20,000 LUX and up. For a simple general rule of thumb, 20,000 lux is around 250 PAR, great for seedlings, OK for Veg, crap for flower.

Click to expand...

Thanks for the info man, i have a lux meter, i might be reading it wrong, directly under the lamp it reads 10xx and gets drasticly lower the futher away you go

Getgrowingson said:

Scrap the plant and start another. an auto looking like that being week 3 it’s a waste to keep it going to be honest. Pop another and wet the soil then wait until the cup you start it in is dry before you water again. Think you overwatered it and drowned it. I would scrap it and start another. You can easily grow a couple oz with that light for one auto. Keep the light start a new one and make sure the soil drys out before you water. Don’t feed until first set of leaves that look like the classic weed leaf. You’ll have much better results. Good luck. Don’t kill it with love and let it grow

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Yeah i was sort of thinking the same myself about starting another, and the last watering it may have gotten a lil too wet but i always let it dry out in between waterings

Smiffy2k9 said:

Thanks for the info man, i have a lux meter, i might be reading it wrong, directly under the lamp it reads 10xx and gets drasticly lower the futher away you go

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Hold it right above your plant, almost touching, and what does it say? hit the X100 button, and read the numbers. If it says 230, then add 2 zeros to it, so it really says 23,000lux,

I had the same issue when I switched from CFL to LED. InTheValley is right about the lux.

20,000-28,000 lux for veg
40,000-50,000 for flower


Had to get my lights closer. My lux would drop off faster the further the LEDs were than my CFLs.

as stated above overwatered if in fact at 25+C ambient temps , and it's an auto= time is not on your side.........I would trash it and start over with a photo fem, get adjusted to vegging under the blurple before flipping

good luck

PSUAGRO. said:

as stated above overwatered if in fact at 25+C ambient temps , and it's an auto= time is not on your side.........I would trash it and start over with a photo fem, get adjusted to vegging under the blurple before flipping

good luck

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I would say photo too, because you can mainline, lst, crop, small scrog, get a nice haul if you veg-manipulate the heck out of it for 45 days or so. Keep defoliating, keep toppin, Flip, defol again at 15 days, then dont touch her till harvest.