NEED HELP. 5 Weeks into Flower. Leaves turning yellow/purple

myke said:
well isnt that cool! cannabis in the wood shop.is that a jointer at the top of pic?
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Lol. Yes. My father just took them in there to take the picture. HOW DARE HE PUT THEM NEAR DUST! It is actually a lathe (however u spell it).
 
Judo90 said:
I totally agree which is why i originally ruled out light burn.

I use a ph tester pen. It is calibrated properly as my tap water is tesing correct around 300.

Day time temps are around 21-24• celcius. When light are off i drop to a low of 18.5 celcius. I have a fan blowing up from the bottom. And one blowing across the canopy. Also using a exhaust fan and filter. So plenty of air circulating.
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You're tap water is testing at 300? That sounds more like ppm than pH. In fact it can't be pH. The pH scale goes from 0-14 and requires special measurement equipment to even measure the extremes on both ends of the scale.
 
undercovergrow said:
how about put some pictures up under regular lighting? it could very well be over-watering at this point. usually soil doesn't need to worry about PH etc. so you might be loving them too much. keep in mind you are growing an annual plant, so at this point don't chase problems. alter your watering schedule and see how the one girl responds as the other looks fine. cannabis likes a wet/dry cycle.
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ShLUbY said:
another thing it looks like to me is K deficiency.... but typically you would see that in the oldest growth first and not the newest, because K is mobile in plants. that's why i'm leaning towards light burn.

can you dim the light any? try switching the plants around, and move the unaffected one to the spot where the affected one is. maybe there is a hot spot in the light itself.

something else I just thought of... if your runoff is 6.8, and going in it's 6-6.5, your soil may be over buffered and it's not remaining acidic enough. pH being too neutral or slightly alkaline would affect the newest growth first for things like Iron, which is important in the synthesis of the chlorophyll molecule itself. so the fact that its going in at 6-6.5 and coming out higher than its going in, should indicated that your pH in the soil is actually higher than your reading because you have to account for some neutralization happening with the acidic watering.

I really don't like using runoff to determine medium pH. You'd be much better off with a decent soil pH probe. Bluelab makes a nice unit, though it's a little pricy at ~145$. but well worth it. when i purchased mine, it helped me dial in the pH of my medium BIG TIME.
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Right now i have both Veg and Bloom light on as recommended. Do you think changing to just bloom (more red) will help at all?
 
At a pH of 7 ur nutes should to take that down to a suitable range. Only time I pH is when I used hydro. Your soil should buffer it correctly .
 
since you're growing in soil, imho you shouldn't be worrying about PH or anything else like EC ... those are more for DWC grows, etc. my original advice still stands - at this stage, try to raise your lights a bit (next grow consider height, etc.). now that i can see your girls under regular light, i still think the one girl just doesn't like the watering schedule as much as the other one but they still look good. remember, this is an annual plant you're growing.
 
Judo90 said:
Right now i have both Veg and Bloom light on as recommended. Do you think changing to just bloom (more red) will help at all?
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yes, more red for flower for sure. my cousin uses those vipar lights and he saw a huge difference when he decreased the blue in flower after a few runs.

Judo90 said:
Damn. Are you telling me i dont have to be PH ING my water everytime? Lol
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you should definitely pH your water. your soil seems too neutral or slightly alkaline based on your runoff. if anything I would be going 6.0-6.2 every time (when i used bottled nutrients that's what I did). that will be neutralized by your buffer that comes in the bagged soil. ensures a better nutrient delivery. cannabis likes 6.0-6.5 soil pH. anything higher than 6.5 tends to inhibit the solubility of iron.

and yes, be sure to calibrate your pH pen, and if you need to buy a new one, Bluelab makes a great product.
 
undercovergrow said:
since you're growing in soil, imho you shouldn't be worrying about PH or anything else like EC ... those are more for DWC grows, etc. my original advice still stands - at this stage, try to raise your lights a bit (next grow consider height, etc.). now that i can see your girls under regular light, i still think the one girl just doesn't like the watering schedule as much as the other one but they still look good. remember, this is an annual plant you're growing.
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he's growing in soil, but he's not doing an organic water only grow and relying on microorganisms and root exudates to determine his pH.

when you feed a plant already chelated nutrients, it decreases the amount of exudates it produces because it's a waste of energy since everything is already available in the solution.
 
ShLUbY said:
he's growing in soil, but he's not doing an organic water only grow and relying on microorganisms and root exudates to determine his pH.

when you feed a plant already chelated nutrients, it decreases the amount of exudates it produces because it's a waste of energy since everything is already available in the solution.
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ok
 
Judo90 said:
Damn. Are you telling me i dont have to be PH ING my water everytime? Lol
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I can only share personal experience. I don't pH, I only check ppm's. My water comes out at 7, after nutes it goes down to 6-6.3. I use promix for the first few weeks then go into 100% perlite.
 

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ShLUbY said:
yes, more red for flower for sure. my cousin uses those vipar lights and he saw a huge difference when he decreased the blue in flower after a few runs.



you should definitely pH your water. your soil seems too neutral or slightly alkaline based on your runoff. if anything I would be going 6.0-6.2 every time (when i used bottled nutrients that's what I did). that will be neutralized by your buffer that comes in the bagged soil. ensures a better nutrient delivery. cannabis likes 6.0-6.5 soil pH. anything higher than 6.5 tends to inhibit the solubility of iron.

and yes, be sure to calibrate your pH pen, and if you need to buy a new one, Bluelab makes a great product.
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Great. I will ph to 6.0 from now on to try to drop the neutral ph run off.
 
DustBomb said:
I can only share personal experience. I don't pH, I only check ppm's. My water comes out at 7, after nutes it goes down to 6-6.3. I use promix for the first few weeks then go into 100% perlite.
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well it makes a lot of sense to not pH anything when it comes out to the desired range lol. plus you're not even growing in a soil type medium, completely different situation
 
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