Yellowish spots on leaves

With my 1-2-3 nutes. Powdered from my local hydro. I’ve been playing with more 3 then 2. 2 is my N.Some of my previous hydro crops after 70 days of flower the leaves are dark green like they’ve been armour alled lol. So been reducing N now. If you’ve ever read about lucas formula does kinda the same thing.
I'm at the beginning so not even thinking of mixing my own nutes. I just want a fairly healthy grow on pre made stuff and learn (so at least I have something to smoke) and then I'll get into more advanced stuff. I've heard coco is harder at beginning than soil but easier once you get the hang of it, not sure if that's true. I've just fed them, will post results shortly. New problem developed. Btw BIG THANK YOU Myke for helping me since the beginning of the thread. I appreciate it.
 

myke

Well-Known Member
I see some cupping of the leaves. Light too close or too much wind from fan or your room is too hot.
 
Hmm, I peek to check temp more or less every hour and it's never above 25 when I look, however over last few days my hygrometer says the highest temp at some point was 27. I've been trying to figure out when. Relocated the fan and I'll try pinpoint when my temp goes to 27 so I can eliminate this jump. This plant is furthest from the light.
 
50-60 during lights on, jumps to 80 when lights are off, I've just ordered a dehumidifier, didn't have that problem when I was watering once a week but now it's building up when lights are off. I just read that cupping can be caused by higher humidity and the plants are trying to 'sweat' so my guess is it's the humidity. What's your opinion?
 

myke

Well-Known Member
Ya RH goes up at night when the room cools.you can try to add heat or get a dehumidifier. The DH will add a lot of heat. What do you have for exhaust fan? Mine runs full speed at night to pull humidity out.
 

myke

Well-Known Member
Oh and yes sweating is what causes a leaf to cup. That’s why I asked about heat light etc.
 

myke

Well-Known Member
When your girls are big and in flower you’ll have even more of a humidity problem with 12 hours of dark.
 
tornado 1500m3, fan controller is set to 22 as it measures the temp at the top of the temp and it gives me constant 24-25 apart from that 27 spike which I still need to figure out. Additional heat source while lights off will be beneficial as it's a bit cold then, 17.
 
When your girls are big and in flower you’ll have even more of a humidity problem with 12 hours of dark.
This means I have few weeks left to figure out how to keep the humidity level stable, may just need to experiment with the fan speed while lights off. I was thinking of purchasing another fan, a smaller one, and plug it into an Inkbird humidity controller but that's a bit of an investment.
 

samoka_loda

Member
Believe it or not I just sat down and thought about giving you an update. My plants are now all very well and healthy, perky leaves, nice colour, the yellowish spots have disappeared. The pH run offs are still high but plants seem to be doing well regardless, although I will never use pebbles again! The one that had cupping on leaves and brown edges was doing a bit rough, I kept taking the bad leaves off but after few days of stable humidity it started recovering and growing new healthy leaves. My vocabulary isn't rich enough to find the right words to thank you for saving my amateur ass. You're a legend Myke!!!
 

myke

Well-Known Member
Good to here. You know after you mentioned the curling edges. I had a look at my plants and I also have one with the edges curled up a little. No big deal I don’t think. They grow so fast.
 
Good to here. You know after you mentioned the curling edges. I had a look at my plants and I also have one with the edges curled up a little. No big deal I don’t think. They grow so fast.
At least I learnt a few things and I'm going to continue to learn. That's right, they grow really fast, they were just tiny cotyledons 6 weeks ago. I'm probably going to see even faster growth next time as I'll have coco where I can actually control the pH.
 
Hello. Thought I would update you again. I've attached a photo this time to see what you think. They're 7 weeks old now. They only look this yellow under mh bulb, don't have a way to take a decent photo with normal light to show true colors.
 

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myke

Well-Known Member
Looks good! Need to do some LST and get a net so you can even out the canopy.Switch to flower should be soon.
 
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