Spotting leading to significant Necrosis

[4d-Rock]

Problem: Spotting appears about 5-6 days after new leaves grow, and degrade over the next 5-7 days until they are pretty much fried. This started with the first set of single leaves and has occurred to every new set of leaves since.

Medium/grow method: 75/25 Coco/Perlite mix with clay pebble layer on top and bottom of 2 gallon smart pot. Space Bucket grow

Feed and supplements used: Using the Fox Farms Trio (not the hydro version), with CaliMagic. Been feeding every watering since seedling. General feed Schedule so far
Week 1: 1ml/L of Big Bloom/Calimagic and 0.5ml/L of Grow Big
Week 2: 1-2ml/L Calimagic, 2ml/L Big Bloom, 0.5-1ml/L Grow Big
Week 3: 1.5-2ml/L Calimagic, 2ml/L Big Bloom, 0.5-1ml/L Grow Big
Always pH to 5.8-6.2

water source: Tap water sourced from nearby lake which goes through a carbon/UV filter circuit. Comes out of tap at 60ppm and 6.8pH

Strain/age: White Widow Auto Fem from Crop King Seeds - currently Day 25 from sprout

light used: 4x 9w (60w Equiv.) LED bulbs, 3x at 3000K, 1x 5000K. 3m LED strip lighting around sides of bucket. Bulbs are approximately 18 inches above plant

Climate: Pretty consistently 20-21C and 55-65% RH

Additional info: Have had a few people in the other forums tell me it's a Ca deficiency.
I have a cheap TD3 knockoff brand PPM meter which I believe is on the 0.5 scale. I've been trying to use it as a guide but weirdly when I add 1mL of Calimagic it bumps my ppm from 60 to 300. Not sure why it's so hot or maybe my meter is messed. In comparison, 2ml of Big Bloom increases my ppm by about 100ppm, and 0.5ml of Grow big increases it by about 200ppm.

Pictures are named based on the day. D19 = Day 19...etc.
D19 - you can see the spots starting to appear on the 3 leaf set
D20 - Spots getting worse
D22 - Leaves are now contorted and dry, 5 leaf set you can see spotting starting to form
D23 - Spots continue to get worse of 5 leaf set, 3 leaf set pretty much toast
D24/D24B - 5 leaf set pretty fried and wavy, new set of leaves starting to be affected

Any recommendations on what actions I should be taking?

 

[AnonymousGrower1]

Don't trip on this. You over fed.

What I would do:

Flush with spring water and stop feeding. Start new seeds. Put these girls off to the side and hope they return to health.

 

[4d-Rock]

That’s interesting, I was always under the assumption that tip burn was the first sign of overfeeding which hasn’t happened. Or are you saying that the over feeding in some nutrients (which may not have been enough to cause burning tips) may have created a lockout of others?

This is a space bucket grow, so starting another seed isn’t an option unless I scrap this one.

If I was to flush, where would you recommend my nutrient levels be at on the next few feeds?

 

[Mike20132]

I'm not sure what the manufacturers feed schedule says for the nutes you are using, and if you already know some/all of this, I apologize..

No food at all first 10 days. The plan't doesn't need it and won't take much (if any) of it up, so it just builds up in the medium. All you should add now are inoculates for the soil/roots (bacteria, etc).

I start off at 1/8 of full strength for day 10-20, then 1/4 strength for the next week or so, until it's starting to really bulk up. Then slowly bring it up to 1/2 strength and watch for burn. Some plants will take more, some will burn.

I do DWC, so this might not apply... but I would flush the hell out of the soil, and drop back to 1/4 strength.

Also, I have not started CalMag until day 21 for this and my last grow, and things turned out fine. With 60ppm water, you might be able to get away with waiting even longer. Too much CalMag has caused some weird pH swings in my tanks. I'm still fairly new, and I am trying to find the "sweet spot" for calmag. Getting closer, but not there yet.

 

[AnonymousGrower1]

You really over fed. Which caused total lockout. Tip burning is the plant saying : Hey, I have an issue! Your issue here is different. The nutrients came in so fast your plants didn't have the ability to react.

That’s interesting, I was always under the assumption that tip burn was the first sign of overfeeding which hasn’t happened. Or are you saying that the over feeding in some nutrients (which may not have been enough to cause burning tips) may have created a lockout of others?

This is a space bucket grow, so starting another seed isn’t an option unless I scrap this one.

If I was to flush, where would you recommend my nutrient levels be at on the next few feeds?

 

[AnonymousGrower1]

If it makes you feel any better, we've all done this. We've all forgot to check pH, or over fed, or ignored a plant. Over watered and under watered. You name it, I've done it.

 

[4d-Rock]

Gotcha, I’m not too upset even though it kinda sucks.
Essentially this is my first Coco coir grow but have 2 semi-successful soil grows. Since it was new I had done a bunch of reading which a lot of people said to feed immediately. Coco has no nutes so the plant needs it. I did start slow as the first week is about 1/4 the recommended dosage, even week 3 is still around 1/2 (using fox farms hydro chart).

Unfortunately there didn’t seem to be many people using Coco, with Fox farms, in a low watt LED stealth setup, growing auto flowers...so I kind of had to improvise, obviously not too successfully.

I’ll try doing a flush and go back to 1/8-1/4 and see how it does. If it doesn’t recover, oh well, lessons learned and try again.

 

[komplex180]

From what ive read, fox farm everything is pretty hot. Nutes and soil. Luckily ur in coco, u can just reset until better.

As far as bumping up on nutes, at 3 weeks u should only be on base nutes and at 1/4 strength. Dont bump up dose until plant starts to lighten in leaf color.


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