Coco, Lucas formula 6/9, LED, Well water EC 0.15, feeding around 1.2 EC, pH from 5.6 to 6.2
was it on newer growth or older growth?
Mostly on older leaves. One plant does have some tip burning and yellowing on bud leaves and has been developing botrytis though. Leaves are developing burned looking spots and a shiny green or bronze kind of color.
Double check your pH pen? Lucas shouldn’t have issues. How old are they?
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I just replaced my pH meter. The old one was not staying calibrated and i was adjusting ph to way too low. I’ve been calibrating the new one every couple of days. The symptoms are on all plants to some extent (8 varieties in all). Some are about 9 weeks (3 weeks into flower) the others are an auto which is around 100 days from seed (60 day strain HA!) and another auto that’s at day 75.
have you scoped for pests?
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I can’t find any pests. They look like some of them are starting to claw a little. Some more pics.
i searched “shiny” on a list of deficiencies and it listed coppy deficiency, nitrogen toxicity, and phosphorous deficiency. also included picture of broad mite damage (they are only visible with 60-120x scope or so) and they can often appear as weird symptoms/deficiencies
phosphorus deficiency
nitrogen toxicity
copper deficiency
broad mites
this is the source i was using : it lists all deficiencies with their possible symptoms and causes
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I was thinking maybe Phosphorus deficiency, but now I’m worried about broad mites. I’ll do some more microscoping. Also I need to get my water analyzed.
That looks a little like high respiration damage. High heat or low humidity can cause it. My other guess would be mites but you should have more speckling.
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I’m kind of suspecting mites right now. Unless there is something weird going on with my water. I’m tapering nutes in the reservoir now by just adding water and Ph Down to flush the coco. After that I’ll dump and clean it and refill with normal strength.
Reasons i suspect broad mites:
The symptoms are on all the plants just different severity.
Plants are different ages and strains.
I recently brought some used equipment into the room.
Reasons it might be just a nutrient issue (wishful thinking?):
I haven’t seen any mites under 30-60x magnification
Symptoms are similar to Phosphorus deficiency with a little Nitrogen toxicity.
I don’t want it to be the case.
I’m about to order a gallon of Flying Skull Nukem. Has anyone used this? A lot of the 502 grows around here use it, but I’ve read mixed reviews and the manufacturer is kind of vague about what it is an how it works.
not seeing mites damage… how often are you watering?.. you got pans under those bags pots
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broadmites not spider mites - @RickSanchez get a 100x scope at least imo, 60x would be very hard to see them i think
Hard but doable. Broad mites suck, but are easy to kill once you know you have them. Diagnosing is a larger problem for most.
They will typically just destroy the tops of the plant. Leaves will twist and twirl and look like they are drying out.
You’ll see some of this
As well as this
That said, Lucas is 8/16 so you are changing the way it was intended to be used so it also could be the food as well. Some also do 5/10 but if you are in coco you need to supplement magnesium and sulfur to keep it up as coco lowers those levels naturally. Just use a lil epsom salt at around 1TSP per 3 gallons and it should fix your plants.
I’ve got a few recipes floating around that are a little more updated than Lucas if you have any interest. @OG1969 is using one of them I designed for the life of the plant through all stages. I’ve also got one for a perpetual setup that I use along with a few of my team guys.
Best of luck at solving your issue, and if you find it is broadmites, hit me up and I’ll help you recover.
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When you changed your meter did you immediatly correct your ph like what was your ph actually at when you changed your meter an what did you adjust it to
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They’re on a drain table. Watering the older plants 3x during lights on. The younger ones are just at 1x a day right now, about to switch to 3x.
Yes it is a modified Lucas formula. I will try adding epsom salt, I was originally thinking it might be Mg related.
i dumped the reservoir and started over at 5.8 pH. I didn’t test but I was using almost double the pH down so it was really low for at least a couple weeks before I realized what was going on. That was three weeks ago though.
I was wondering if it could be the ph swinging so drastically so soon but im sure it would show quicker than that
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I’ve not witnessed russet mite damage first hand, and I guess they could have hitched a ride if you brought in some used equipment… The damage looks a bit more focused and sporadic than I’d associate with tiny bug bastards, but again… haven’t seen their damage firsthand.
The crinkley-leafed plants look like they have a different problem altogether… it looks more like bleaching than necrosis, and actually looks a bit like my mysterious-but-maybe-LED-burn problems of over the summer. When I’ve had Mg deficiencies, the symptoms seem to have been more evenly distributed over the leaves, and fairly gradual in onset (at least initially).
I’ll see myself out. Hope you can pin down this problem soon, and I’m betting against mites for whatever that’s worth 
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