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[GhettoStyle]

The age of the plant is about 3-4 weeks ago
, this photo!
Canna aqua fertilizers

[Bluey]

I think all types of growing are great ways to learn to grow.

DWC is too but it's more difficult to manage. Soil offers buffers re pH & EC & is less critical re plant health. It also requires less time and far less can go wrong in a soil grow than DWC so less to troubleshoot which I think is the point Smallgrow is making

[YYCannabis]

I’ve only ever done DWC right from the start. Never grown in dirt or coco.

I’m curious as to why people think DWC is some extreme exercise in growing? Only thing that i need, that a dirt farmer doesn’t need, is an air pump. I would go so far as to say that DWC is a great way to learn to grow.

[Smallgrow]

I would contribute that DWC or hydro in general is perhaps the most advanced way to grow. The results can be excellent for experienced people no question, but when I see people say “ it’s my first grow and I’m doing DWC” I just shake my head.

Get a high quality cannabis specific water only soil and grow a couple plants. Maybe a top dress or two along the way.
Do your research and practice growing at level 1 before you jump to level 11

[Bluey]

I agree with what you say re working out what has happened, it has already happened and we don't know what the OP was giving it last week, when I suspect the plant was smaller and couldn't handle, I assume, 0.8EC....because that's nute burn on the tips and along the margins every way I look at it from the earlier growth when it was less mature. That's how I see it. Yes leaves can look like that from deficiencies but I've found in the past it's because of damage to the stem stopping nute uptake.

The new growth is looking better but I still recommended a minor adjustment downward on the EC just to be cautious. If his DLI measurements are accurate that should be fine.

Keep in mind you can keep a plant 30 times that size perfectly healthy with an EC of 0 3 and no signs of deficiency with a DLI as low as 6 to 7.

His DLI at 15 is probably a fraction low if giving 18/6 schedule but fine to help the plant recover from the earlier setback.

Increasing EC is the risky approach IMHO, even though the plant is at a stage now that if it were healthy would normally handle 0.8 or even a bit more as you have said.

I err on the cautious side

[YYCannabis]

Here’s a screenshot of my rather lazy spreadsheet tracker. I highlited an issue where water level wasn’t dropping in my DWC. The PPM (I prefer PPM over EC) didn’t vary much over those few days. This is a sign of lockout because she was barely sipping water instead of drinking it up. She was fine at 1440 PPM but locked up when it climbed to 1500 PPM. So i lowered the PPM once. After a few days of recovery, i lowered my PPM again because she wasn’t recovering as fast as i had anticipated.

[YYCannabis]

More info is needed to give better diagnosis and guidance

For the poster to just say here’s my EC/PPM/pH etc is only a snapshot of the details. But for experienced growers like you and me, we know that the trends over a few days tell a more informative story. What was the EC yesterday and the day before? Did the EC rise or fall over the last 3 days, or since last feeding? Is the water lever dropping? Is H2O dropping and the EC is climbing?

Nute lockout and nute deficiency almost always present the same symptoms because they are essentially the same issue, but just have different causes. Only difference would be H2O uptake; if she’s drinking plenty of water, then it’s a deficiency, but if she’s only sipping water, then it’s lockout.

From counting the nodes on the stem, this plant is too mature for the current EC level and, in my opinion, is starved for more nutes.

[Bluey]

So there you have it. Two completely different opinions that are actually opposing as to both the problem and recommended solution.

[YYCannabis]

Nutrient deficiency is the issue.

Without much more info it can be hard to help. Age of plant? Photo or auto? Nutrient type?

Since you’re new to this, I’ll help to explain what I see:
1 Yellowing Leaves (Chlorosis):
2 Widespread yellowing, starting from the leaf edges and tips, indicates a nutrient deficiency, likely nitrogen or magnesium.-The older leaves are more affected, suggesting a mobile nutrient deficiency (these nutrients can move from older leaves to new growth).
3 Brown Leaf Tips and Edges (Necrosis/Burnt Tips):-This often points to nutrient burn or an excess of salts in the root zone (common in hydroponics if EC/PPM is too high).
4 Leaf Curling and Damage:-Some leaf edges are curling down or showing twisted growth. This can indicate pH imbalances or environmental stress (e.g., heat stress, low humidity)

.Possible Causes:
-pH Imbalance: If the pH of the nutrient solution is outside the ideal range (5.5–6.2 for hydro), nutrient uptake is impaired.
-Nutrient Deficiency: Insufficient nitrogen, magnesium, or iron could cause chlorosis and necrosis.
-Nutrient Toxicity: Overfeeding or nutrient salt buildup can burn leaf edges. (Probably not this because your EC is too low for a plant this far into veg)*
-Root Health: Poor root aeration or root rot can cause similar leaf symptoms.

*Just as a side-note….With an EC this low, the chlorosis and necrosis symptoms are likely due to nutrient deficiencies rather than toxicity. Even though 0.7–0.8 EC is typically suitable for very young seedlings, this plant looks a bit further along and would need higher nutrient strength.

What’s Happening:
-Nitrogen deficiency: Lower leaves turning yellow (mobile nutrient).
-Magnesium deficiency: Interveinal chlorosis seen in older leaves (also a mobile nutrient).
-Possible Potassium deficiency: The burnt edges on older leaves can be a sign of K deficiency as well


Recommendations:
Check pH: Ensure the nutrient solution is between 5.5–6.2.
Check EC/PPM: For young plants or stressed plants, keep EC around 0.8–1.2 mS/cm (400–600 PPM).
Flush and Reset: If there’s a salt buildup, flush the system with pH-balanced water and reintroduce a balanced nutrient solution.
Check Environmental Conditions: Ensure proper light intensity, temperature (22–28°C), and RH (50–65%).
Inspect Roots: Check for healthy white roots. If roots are brown or slimy, root rot may be present.

Recommendations for Correction:
Increase EC gradually: Raise to around 1.0–1.2 mS/cm (500–600 PPM) to provide a more complete nutrient profile.
Use a balanced veg nutrient: Ensure the solution includes Mg, Ca, and micronutrients.
Keep an eye on new growth: If new leaves come out green and healthy after adjusting EC, you’ve corrected the deficiency.

[Bluey]

You've burnt the crap out of them and have nute lockout as a result.

Drop your EC back a fraction. 0.6 should be fine. Set your res at 5.8 and reset daily. C/o nutes weekly. Ensure no light can reach your res solution, everything blacked out. Use an anti fungal.

[alltatup]

GhettoStyle In spite of the name of this forum, growing good, potent weed isn't all that easy. Dude, with all due respect, you need to do some reading and studying if you want to do it right: https://www.growweedeasy.com/why-cannabis-leaves-yellow

[GhettoStyle]

DLI 15
temp 25C
res 21C
EC 0.7-0.8
pH 5.7-5.9