HELP! Help

[GhettoStyle]

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

[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

[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.

[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.

[GhettoStyle]

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

[Bluey]

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

[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]

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

[GhettoStyle]

Dear friends, I am at a loss as to what to do. I don't understand what happened! From the start, when I connected the system, the reading was 200 ppm. It was tap water with a concentration of 100 ppm + 100 ppm CAL-MAG.
Then, I added an extra fertilizer 100 ppm, and it read 300 ppm total! But the next day, added more fertilizer +100 ppm. The next day, the problem with the leaves started.

[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.

[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 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

[GhettoStyle]

I don't like growing in the soil! in my opinion DWC is a more advanced and cleaner way.

[Rootsruler]

I agree with Bluey. While some may be able to master DWC from the beginning, most new growers don't take the time to learn the intricacies of growing in DWC. They aren't used to being responsible for EVERYTHING the plant needs.

I would agree that starting in soil is the best way to understand the biological processes that happen along with having the time to correct whatever mistakes new growers make.

I started in hydro because I heard it was the fastest, cleanest and most productive way to grow weed. I was like most newbs and jumped into it thinking it would be easy having grown vegetables outdoors. I wasn't prepared for all that went into it and failed. In those days the only info source there was was other growers. No internet forums. I decided to try again but outdoors. I had more success and continued but learned a lot about the bio processes that happen rather than just water and watch them grow. My outdoor grows got better and when I moved up to NorCal they got exponentially better having a few of the hippies I worked for take me under their wing and teach me what they had learned over the decades.

[SWFL]

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

Are you using some sort of hydroponic system?

If so I would bring the pH down a tad closer to 6.5.

Likewise how are you chilling your nutrients, do you have a good flow rate from reservoir to tank, if not your tank temperatures could be higher compared to the reservoir, the temps if too high which can retard nutrient uptake plus high tank temps can result in root rot.

I found a temp around 73F is ideal.

[GhettoStyle]

I don't quite understand your question about using a hydroponic system???!!!!
and why do you recommend such a high pH?
I use an aquarium cooler!

[SWFL]

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.

I have never used any other method,the reasons are many, due to the location I need a short winter growing cycle plus I have very limited space, soil just wouldn't cut it for me.

Hydroponics is an excellent and easy way to grow, but needs to be monitored daily as things can go very wrong quickly if not caught in time.


,

[Bluey]

How are you measuring pH and with what and how often? Pic of the pH pen if your using one please GhettoStyle

[GhettoStyle]

I measure it 1-2 times a day! pH metr Sanxin

[GhettoStyle]

[Bluey]

If using dwc you should let it rise to 6.5 or even a tad more before correcting it.

I wanted a photo of your pen not one from the internet but anyway.

I'm not familiar with that brand but their top of the line pen appears to be a rip off of the Apera PH60....which is a lab quality pen..its what a lot of us use where pH is critical. Available at the Amazon apera shop.

Do you calibrate it?

[GhettoStyle]

Dear friends, could you please let me know up to what level (EC) or (PPM) you are adding cal-magnesium?
I am using tap water with an (EC) of 0.2
so what level should I add cal-magnesium to it?

[Bluey]

Not much here. At most 0.25 but often only 0.1

[YYCannabis]

Does the BAC bottle say how much to use? (Their website has almost no useful product info)

[GhettoStyle]

Friends, if the pH drops, then you need to raise the EC?

[GhettoStyle]

I have an airstone! This is the main thing in DWC! I thought the pH was dropping because there weren't enough nuts!

[Bluey]

What EC are you currently using and how often are you emptying and refilling the tank with fresh?

[GhettoStyle]

I raised the EC to 1.1 545ppm
I change solution every week

[YYCannabis]

Some questions for you:
1) What are you using for the DWC set-up? (5 gallon pails or something else?)
2) Are you using the full compliment of the Canna Aqua nutrients? Or only some of the products?
3) Are you following their feed guidelines? (See the image i attached from their website)
4) As a new grower, avoid adding nutes between water changes. Plants absorb nutrients at different ratios, so adding more nutes might provide some of the nutrients it’s looking for, but also risk creating too high a concentration in other nutrients.

I’m a DWC guy with a few years experience. Even now, if i have a nutrient issue that has me struggling to understand the cause of the problems, i do a full water change instead of cheating the nutes between water changes. Nutrients are cheap when a plant is that small.

So, to get on the path to getting that plant healthy:
1) do a full water change and follow the Canna Aqua feed schedule. From looking at that plant, your re still in the “Vegatative Phase I” of their feed schedule. (Line 2 of their guide).
2) Add your CalMag additive following the directions on the product.

[GhettoStyle]

Yes, I use 5 gallon pots! The other day I raised the pm from 300 to 550 ppm and now the plant has stopped growing and the pH has started to drop from 6.0 to 5.2-5.3 every day! in my opinion, the feeding schedules from the manufacturer are very high! since it says 3-5 days and 520ppm in the table, these are big values! so I tried to make 550 ppm at week 3, so the plant stopped growing and the pH began to drop every day.

[GhettoStyle]

it looks like I killed the plant so badly that it won't recover now((
initially, it was on water with calcium and magnesium 200 ppm and then I added nuts and made 300 ppm and then after a couple of days I made 400 ppm and the first symptoms of necrosis appeared
here is a photo of how the plant looks now! I cut off the bottom leaves as they are almost completely dry!


I also read about deficits on the forum! and I don't understand NPK mobile substances, so the symptoms will always go from the bottom up! Magnesium is also mobile! but calcium and sulfur are not mobile and the symptoms start from the top at a new growth! so the photos that I took today show that chlorosis is present on the newest leaves!!!

[Bluey]

Check the roots....take a pic. Give them a rinse too. What color?

[GhettoStyle]

The roots are white! I can take a photo later!

[Bluey]

Sounds good