New FSeries Build. Plants drooping

[FarmerP]

First time poster long time follower.
Recently finished my fseries light and moved it into the new setup. Haven’t grown in several years, decided to kick it off again as I’ve got a new house with plenty of space. Previously used a 1000w DE Gavita. Constant temp worries in the past with this. 4 soil grows under my belt with moderate success.
Shoutout to everyone involved in previous build threads who opened my eyes to the LED game. ANC, Randomblame, Takeshy etc. Great reading.

Added the new light 7 days ago.
2 x HLG-480H-48B
10 x 4ft 3000k strips.
Pot set at about 80%
Raised 30 inches or so above canopy.

5x5 tent. Plan is to use this for flowering and setup an old 3x3 for veg with an old kind blurple.
First DWC grow 5 gal.
3 bag seeds in week 6 of veg no sex shown yet with some ethos seedlings underway.
Using the canna nutrient line @ 2/3 strength
PH on res change 5.5 creeps up slowly over a few days.
Temp 78. I can increase this if anyone recommends?
No Co2 but from what I’ve read I may need to add when I crank up this light.
Humidity +- 55%

Problem.
2 of the the 3 are drooping, yellowing and growth has stunted. The last plant seems to have exploded and taken to the fseries very well.
No change to the nutes. Only change has been the light. The symptoms look to be more of an issue with the dwc than lighting so I can move this thread elsewhere if needs be. Both of these drooping plants were in perfect health up until the light
Temps are good in the buckets and root systems are all clean and healthy.

Any input or help would be great.
Thanks



First Pic showing plant which continues to do well.

Second shows the droopy girl.

 

[FarmerP]

I will add some pics of the light later for any DIYers who may be interested.

 

[jcdws602]

Could be light stress. Happened to me when I switched to led. First few days it wasn't too noticeable but about a week in some of my plants started drooping. The next few days some yellowing started. I thought it was a nutrient and or ph problem but upon further research I concluded it was light stress from the leds. I dimmed my lights from 80% to 20% and within 24 hours my plants started to show signs of improvement. If everything else is on point it could be the light intensity.

 

[Rocket Soul]

Are you in flower or veg?
My rec is higher temps and lower the output (especially if your in veg) on your light, wait for healthy green gorwth

 

[FarmerP]

@jcdws602 sounds like I have a very similar situation. It was 4/5 days before the problem really showed. Dimmed to 20%?? That’s one hell of a drop. Maybe I’ve underestimated the output of these lights. When increasing the power what percentage did you find the sweet spot for vegging?

@Rocket Soul
I’m in veg. Currently in week 6 with these bag seeds.

Definitely sounds like I need to turn down the sun from both responses. Currently in work I’m going to call the wife to get her reduce it ASAP!
Appreciate the help

 

[jcdws602]

Yes dim low and once they recover slowly acclimate them to the led lights by increasing the intensity gradually. For example, every 2 days bump it up 5%. Only do this once they have fully recovered. I know it is counter intuitive to give less light but these leds aren't like hid. The light is more concentrated in one area opposed to hid lighting which spreads. Right now am vegging 8 plants in a 32x32 inch tent with a 240 watt lm301h board 3500k. I have it at 50% @ 20 inches away. The growth is compact.

 

[FarmerP]

Brilliant. I’ve dropped it to 20% now. Hopefully they’ll recover and I will bump gradually as you’ve said. I will follow up with an update when I hopefully see a change.
Think I got carried away with the new light. Too much intensity

 

[Rocket Soul]

Remember when you're in veg the total amount of light you give in one day is 50% more due to longer hours. If you where 80% at 2x 480 drivers you're at approx 30w per foot which is reced for flower, but with the extra hours it's as if you where giving 45w per foot.

 

[OSBuds]

https://www.rollitup.org/t/correct-temperatures-with-leds.1036037/#post-15901080

 

[DukeFluke]

Is your exhaust running full speed?

Try this little trick - turn off your extraction completely, or at least down to where it's just keeping negative pressure. This will raise the temps and humidity. See what effect that has

 

[Rocket Soul]

Is your exhaust running full speed?

Try this little trick - turn off your extraction completely, or at least down to where it's just keeping negative pressure. This will raise the temps and humidity. See what effect that has

Another trick to keep temps up is to extract from the bottom instead of the top.

 

[FarmerP]

https://www.rollitup.org/t/correct-temperatures-with-leds.1036037/#post-15901080

Interesting read there. Thanks OS

 

[FarmerP]

Another trick to keep temps up is to extract from the bottom instead of the top.

I’m going to move the extraction down.

@DukeFluke not on full power. It’s running at about 20%. I think if I bring it down to extract from the bottom I’ll reduce it further down to about 10%. Passive intake only. Helpful tips.
I definitely prefer worrying about raising temps than lowering. That DE gavita I have was like a furnace in the 5x5 tent.

 

[DukeFluke]

If smell isn't an issue, turn it off completely. Make it hot and humid in there, turn your lights back up to a decent power and raise them up high. Make sure there are no issues with cold roots either. They need to be warm before your lights come on.

 

[DukeFluke]

Another trick to keep temps up is to extract from the bottom instead of the top.

Good idea, but if you do that in a tent make sure to close off the bottom vent flaps or you'll just be sucking in air from one vent and straight out through the fan. Leave open the top extraction port where your outtake is atm and close the bottom vents.

 

[FarmerP]

Second full day after reduction to 20%. Two at the back are now perky again and returning to normal colour. Temps at about 80 by day 72 by night.
Im going to leave it at 20% for another day or two.

 

[FarmerP]

Lights bumped. Incredible bounce back.
They’re in week 7 of veg with probably a week lost due to the stress. Think I’ll give them another week or 2 before 12/12 and praying for 3 girls

Thanks again for the help

 

[DukeFluke]

There ya go brother. Nice job

I think this little extraction tip will sort out the majority of LED teething problems.

 

[OSBuds]

" Cultivation under high photosynthetic photon flux density (PPFD) using LED technolo-gy is an emerging technique, and depending on your plant-growth facility, there may be some environmental variables you need to adjust in order to achieve your cultivation goals."

 

[FarmerP]

" Cultivation under high photosynthetic photon flux density (PPFD) using LED technolo-gy is an emerging technique, and depending on your plant-growth facility, there may be some environmental variables you need to adjust in order to achieve your cultivation goals."

This was a nice read OS thanks.

Update on the girls. They seemed to max out at 35-40% while vegging under this light. Stress seems to creep in when I go above that mark.
Hopefully I can safely crank it up soon as I flipped to 12/12 two days ago.
Temps dialled in perfect and holding at 82 day and about 75 night.
RH @ about 60%.