Thrips to black spots to leaf tips curling up.

Hi all,

First time grower and hoping someone can help me out in diagnosing this. I am just starting week 4 in flower and in a 3x3 tent. Using 2 sp150 leds, and a good inline fan. My Temps range from 73-79 during the day with 39-43% humidity and at night it's around 69 and 45% humidity. I started noticing thrips and began to worry when I saw my buds beginning to brown a bit at the tips. I treated a few times and most seem to go away altho I still see some.

I then began noticing some black spots on the underside of my leaves but not on top and they do not rub off and are not raised up.

My leaves seemed consistent with thrip damage but also around the same time it seemed I went from watering a gal a say to every 2 or 3 days. Now it's barely using up any water, nothing like it was. I'm wondering if I'm at the same time experiencing nutrient lockout?

I'm using a nutrient regimen as well. NFTG. I do a feed, feed, tea, feed, feed, flush regimen. I check the ph and ppm with blue lab pens. I have cheaper backup pens as well. It's normally in the proper 6.3-6.8 range and running around 1320ppms (ppm700) per feed currently.

So besides the leaves beginning to drop farther down and brown and the tips becoming crisp and dropping off, more so at the bottom first, today I check and see new symptoms. My very top branches and leaves. Many of the top leaves are all curling up now. Not the sides, just the tips. Plus some of the leaves are also looking a bit sad up top now. I don't want whatever this is to ruin the harvest or stunt it. Is it possible this is nutrient lockout as well? Maybe I have a mix of issues I'm not sure.

I use reverse osmosis water with the nutrient mix I use if that matters. Could this somehow be a calmag deficincey as well seeing as I'm using RO water? Even tho my nutrient line is organic and calcium based? Either way, I believe I will be switching over to a tap water/ro mixture. That leaves the water itself at a 7.5ph with 140ppms. Pictures below. Thank you all advance. I'd hate to see my first crop get ruined at this stage.

I should add that I spent a few days cutting the bad leaves and looking at them thru a handheld 60-120x magnifier and all I could find as far as bugs were thrips.

Sorry for all the pics and info. I wanted to be as thorough as possible. Adding some more of the leaves and bud. And then I'll add one of the plant overall as I see that's helpful to people.

Just noticed some more black spots on some other curled leaves. One thing I didn't mention is light distance. It's about 15 inches away

I took the leaf off that was curled and attempted to look at it under 60 and 120x mag. I think I got part of a black spot inline with it. Not sure if that helps either. Sorry for the bad pics. I was going to do a flush today to see if that helps. Even tho it's still full of water, it hasn't seemed to use any in a day or so. Yesterday's reading is coming back the same today for water.

What medium are you growing in?

Sorry, I knew I forgot something. I'm growing In a 5 gal cloth or whatever they are bags. I'm using fox farm ocean forest soil. The recent lack of water usage seemed to have started maybe in the last week or so. Like week 3 of flowering. Week 4 started today. The other issues were Goin on a bit longer.

I see black spots and think fungus.

Yeah I was hoping it isn't fungus. Anyway to fix that? and isn't that caused by high humidity? Originally I thought the spots were from thrips but they seem to be in the leaf. And not all leaves with it have had thrip type damage. Not really sure how that came to happen. Am I going to be able to have a proper harvest?

I would think copper in some form at this point. Copper sulfate. Bordeaux mixture.

Thanks I'll check into that as well. Looks like a fungicide? Not really sure how I'd apply it but can a fungicide be used 4 weeks into flower?

F33 said:

Thanks I'll check into that as well. Looks like a fungicide? Not really sure how I'd apply it but can a fungicide be used 4 weeks into flower?

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That’s a question for someone else as I’ve never had to deal with it at this stage.

OK. Appreciate your input!

I just read, like most other things, treatment should be used before and not during flowering :/

This seems to move fast. This morning this one leaf only had a few spots on it. Now all the leaves on it do.

I looked at those wpots really big and doesn't look fungal. Looks a lot like thrip damage but I couldn't see any. Means nothing tho as you've been handling that leaf and they just jump off if something disturbs them.

If there are thrips you should be able to spot them I can as long as I have my reading glasses on. A magnifying glass helps.

I hate having shit go sideways when you're just getting into flower.

Yeah definitely thrips I've found many and I've treated a few times. I still find some even on my top leaves here and there and try to pull them off when I can. I was worried those black spots are fungus but glad to hear it may not be. It does seem to be spreading tho. More and more leaves are curled up each time I check. I think I may have multiple issues, not sure. But yeah, it sucks to have these issues the first grow lol

Below is a pic I've gotten of the thrips

what did you initially use to spray for thrips?

I initially used organicide. Being a first time grower, I didn't know the importance of preventative maintenance for that, plus I had gotten the plant from a friend with an invested grow that I realized later on. I also treated once with neem and then again with organicide. My plant also went from using a gallon a day to not needing anything for 2-3 days so that's a concern. I'm wondering if that there could be a calmag deficiency or if the thrip problem is that bad it's really stunting my plant.

F33 said:

I initially used organicide. Being a first time grower, I didn't know the importance of preventative maintenance for that, plus I had gotten the plant from a friend with an invested grow that I realized later on. I also treated once with neem and then again with organicide. My plant also went from using a gallon a day to not needing anything for 2-3 days so that's a concern. I'm wondering if that there could be a calmag deficiency or if the thrip problem is that bad it's really stunting my plant.

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Thrips won't cause them to stop drinking but fungus gnats and root rot can. Are you letting them dry out good between waterings lie so the pot feels quite light?

To get rid of thrips or mites you need to spray really good like every tiny bit of every leaf every 4th day for four treatments. 3 treatments maybe but I like to tack one on to be sure. I just used Safer's End All with 10ml canola or neem oil added. Got rid of mites I'd been screwing around with for two years.

Not something I'd do in flower after the first week and even then only as a last resort. I had 27 plants and thrips all over. I'd sit on a pail and hunt them down by hand for 2 hours every day to bring the crop in. Still got a decent crop but cost me way more labour than usual.

Just remembered you only have a bit to worry about. Happy hunting.