RH too high, heat stress or light stress??

PopAndSonGrows

PopAndSonGrows

Well-Known Member
PXL_20211105_030202950.jpg
I have this really picky White Gold (in front, ignore the starving one in tan pot) and I can't figure out WTF. . . .. It's in 3gal farbric pot, coco, GH 3-part plus Si, Ca Mg and Floralicious. ... At the end of 11/13 light cycle it looks like this:
PXL_20211105_135348915.jpg
Temp is only getting to like 84 degrees at the canopy tops. But, RH has been high here since we finally got rain, like 60%+. The light is more than 24 inches away but is very oversized for the space and dimmed to 55%.

I'm personally leaning toward high RH because it's not something I usually deal with, the heat isn't as bad as it's been in the past with 0 issues, and the canopy PPF is like 600 (with a phone app, but still that can't be too far off). I'd like some advice from those who know better than me. Thanks in advance !!
 
PopAndSonGrows

PopAndSonGrows

Well-Known Member
catdaddy516 said:
I don't think that's an rh issue. It looks like more of a heat issue along with the light intensity overwhelming the plants. How close is that light to the canopy and is it at full power?
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TSW 2000 is literally ziptied to roof of 2x2 tent, was at 70% but lowered to 50%, about 24 inches away.

It definitely LOOKS like heat stress but I've had it hotter with no issues. Other WG is fine.
 
OldMedUser

OldMedUser

Well-Known Member
I got the same kind of upper leaves on some small plants I just moved under a 400W MH and it's just light stress. Low Mg is going to yellow out older fan leaves before it does anything else so that's not it. Could be the issue with the one in the tan pot tho. Epsom Salts fixes that fast.

:peace:
 
C

catdaddy516

Well-Known Member
OldMedUser said:
I got the same kind of upper leaves on some small plants I just moved under a 400W MH and it's just light stress. Low Mg is going to yellow out older fan leaves before it does anything else so that's not it. Could be the issue with the one in the tan pot tho. Epsom Salts fixes that fast.

:peace:
Click to expand...
Yeah, that's what I had to do, but I did a foliar spray instead of adding it to the medium.
 
OldMedUser

OldMedUser

Well-Known Member
catdaddy516 said:
Yeah, that's what I had to do, but I did a foliar spray instead of adding it to the medium.
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Foliar spray is great for a quick fix but should water some in at a tsp/L for a lasting cure. Great for later flowering when the plants love extra Mg and the S is the secret ingredient in bud boosters to help produce more resins and terpenes. More K too to help fatten up the buds while reducing N and P after the stretch.

:peace:
 
C

catdaddy516

Well-Known Member
How long is the medium staying wet? Are you allowing to dry out properly before watering again. Another thing, ph might be too low. What i did was flushed with a mild solution, then fed through the leaves (foliar) with that same solution later on that day.
Raise or dim down that light, let them recover, then increase the intensity little by little (up to 70% for veg).
 
PadawanWarrior

PadawanWarrior

Well-Known Member
PopAndSonGrows said:
View attachment 5023086
I have this really picky White Gold (in front, ignore the starving one in tan pot) and I can't figure out WTF. . . .. It's in 3gal farbric pot, coco, GH 3-part plus Si, Ca Mg and Floralicious. ... At the end of 11/13 light cycle it looks like this:
View attachment 5023089
Temp is only getting to like 84 degrees at the canopy tops. But, RH has been high here since we finally got rain, like 60%+. The light is more than 24 inches away but is very oversized for the space and dimmed to 55%.

I'm personally leaning toward high RH because it's not something I usually deal with, the heat isn't as bad as it's been in the past with 0 issues, and the canopy PPF is like 600 (with a phone app, but still that can't be too far off). I'd like some advice from those who know better than me. Thanks in advance !!
Click to expand...
I'm thinking maybe it's pH or lockout is coming. How much CalMag are you using? If it's was me I'd stop using everything but the GH 3 part and see how they respond.
 
PopAndSonGrows

PopAndSonGrows

Well-Known Member
PadawanWarrior said:
I'm thinking maybe it's pH or lockout is coming. How much CalMag are you using? If it's was me I'd stop using everything but the GH 3 part and see how they respond.
Click to expand...
I use 1/2 tsp cal mag per gal, and 1/4 tsp Si. Always, tapering off both about week 7 flower. I always make sure my fert water is pH to about 6 but it doesn't mean something didn't slip my attention, I'll keep an eye on that too, thank you
 
PadawanWarrior

PadawanWarrior

Well-Known Member
PopAndSonGrows said:
I use 1/2 tsp cal mag per gal, and 1/4 tsp Si. Always, tapering off both about week 7 flower. I always make sure my fert water is pH to about 6 but it doesn't mean something didn't slip my attention, I'll keep an eye on that too, thank you
Click to expand...
That's not much CalMag and Si. I don't grow in coco, but it just kinda looks a little like when I've had a slight Ca toxicity. Are you watering to runoff? And are you pHing after the nutrients are added?
 
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