Gaia Green Grow Tent Leaf Burn Help :(

Hi guys , any help here would be much appreciated.

I had amazing success in veg stage using Peat Moss, Castings & Gaia Green 444 & 284
Then passed them into the flowering tent and somethings clearly now right... Am I frying the plants with those lights so close ? Pics are now at week 6. Any help would be much appreciated.I’m using 620w of quantum in there .

Water Ph 6.3-6.8
recharge & molasses once a week

If they looked good when you put em in there, I would back off the light..
See how they respond..

- Have you experienced this issue with this same flowering tent light and other strains/grows?
- Temp/humidity levels?
- How often do you water? And how much?

Gaia Green products are very light, so I doubt the issue here is toxicity. My first thoughts upon viewing the photos are either 1) excessive watering or 2) low humidity.

Humidity issues are my guess, not really seeing any "phantom" deficiencies/toxicities that would point to pH/over watering.

It looks like what's happening here is the low RH% combined with your HID lights (LED are VERY much high intensity) is causing a "vacuum" (or VPD) and the low RH%+light is causing the water to literally be sucked from both your pots and plants themselves.

I had this problem when I grew under my DE bulbs (almost as powerful as quality LEDs). Anytime my RH dropped below 50% my plants would suffer and looked very similar to yours. When I got the humidity back to 50-60% the plants perked right up.

DE and LED lights have a wider spectrum, as we all already know. As a result of this, the plants have more usable light. More usable light = more photosynthesis.

I ran 50-60% RH all throughout flower; you'll never see mold if you're sanitizing your room, keeping things sterile, and providing sufficient airflow. If you get mold/mildew from high RH then your airflow isn't up to snuff.

Lights can definitely be moved up a tad as well. Hopefully that LED has a dimmer feature of some sort too.

My plants loved every watt from my 1000w DE HPS right up until week 6 of flower. Until week 6, the plants could not get close enough to the light and it somehow did not cause burn. Week 6 came and they started suffering. It wasn't until week 8 that I thought to dim the light down to 600w, but by then it was too late and I'd already lost yield. Buds would have been a lot more flavorful and fatter if I dimmed lights at week 6.

Sounds counterintuitive to back off light during the last few weeks of the plant's life cycle, but consider how it works outdoors. Sunlight is very intense and lasts for 14, almost 15 hours until summer happens. Then, not only does the light cycle get reduced, but so too does the intensity of the sun.

Hope that helps in some way.

Wow . Thank you so much for such a detailed reply. Legend.

Its actually my third grow but first time with organic. I water them when it’s completely dry an inch deep into the substrate.
Temp 24 day 19 at night
humidity was in mid 40s as the room has an AC and it must be too dry in there. Turned off the AC to see how they do .
Many thanks

Glad it was useful, and thanks for confirming my suspicions. I'm even more confident the humidity is your issue here.

Vapor pressure deficit (VPD) used to be something that only multiple light/warehouse growers had to worry about back in the single bulb days, it was rare that home-growers would encounter VPD related issues. But, with the advent of such powerful lights (COB, Cree, DE HPS, etc), a lot more people are experiencing this issue now.

Take a look at the chart below



At 24C, you want 50-60% RH to avoid excess evaporation and your plants drinking excess amounts of water.

I literally never encountered this issue in all my years of growing until I grew under a DE HPS. My temps were always 22-26C, but the plants would just look like shit any time the RH went below 50%.

Hopefully turning off the AC doesn't fuck with your temps, worst case scenario you can always just grab a humidifier.

All the best.

Men my vpd suck in summer lol 1.6 at 29 celcius

How big are your containers?