brown/copper spots on leaves

these spots started showing up a few days ago & don't look like the nute burns I've seen in the past. much more copper colored.

I'm told this is blueberry, and the mother they came from tasted a bit like blueberrys, but all I really know for certain is that the original beans came from a farm near Vancouver. when they were little, they were pretty fert sensitive, but have been on the Fox Farm soil schedule at full strength for prbly 4 weeks now.

3 weeks into flowering
medium is Ocean Forest,
Big Bloom, Grow Big, & Tiger Bloom once per week according to FF's soil schedule. Plus, 1 TBPS molasses/gallon. last feeding was 12/27. each got about 4-6 cups to drink. did one watering last week w/ just water & molasses. also switched from regular tap water (PH 8 adjusted down to apx 6 w/ lemon juice) to Brita filtered water that comes out apx 5.5 PH.

under 400 W HPS, apx 18" above & plants are LST'ed. This one has several leaves w/ these spots & it's prbly the farthest one from the light. The closest one has 2 leaves w/ these spots, but they aren't the leaves closest to the light, so I don't think it's burn. Others are fine.

from the pics on one of the problem threads, I'm guessing MG? IDK.... complete noob here...

sup.... i had similar spots on my ww's and am still trying to figure out what exactly is happening. Im 3 weeks into veg with no nutes using roots soil. I have just started adding the nutes earlier this week. I was told...... that sometimes cannabis will canabalize itself for nutes which makes these brown spots occur..

i have the Jorge Cervantes book and ur symptoms are like K deficiency (lack of potassium). Book says...plants appear healthy with dark green foilage. Leaf margins turn grey and progress to a rusty-brown colour, and then curl up and dry. photos show dark green leaf with rusty tips.

mine did exactly this and some calmag cleared it right up.

dodobird said:

K deficiency (lack of potassium).

Click to expand...

Yep.

All the info you need is in here:
http://www.icmag.com/ic/showthread.php?t=11688

thx for the responses, but I did a little closer inspection this morning w/ a piece of paper & magnifying glass & it appears to be spider mites... fvck

You may very well have spider mites, too, but they're not causing those uniformly-arranged burned leaf points. The damage patches they leave are much more random and more in the soft tissue of the middle of the leaves.

Personally, I subscribe to Uncle Ben's theory that "bloom foods" are unhealthy for plants, esp in early flower where there is still a lot of active vegetative growth, too. And, I find Foxfarm stuff really strong, and really acid.

Did you pH-up all those feeds? Hope so -- FF liquids are acid as all get-out. The "feeding schedule" also causes a build-up of excess nutes; it's overkill. You will likely see this problem get worse before it gets better, even if you fix it correctly. It will take time for that excess to work out.

Check this out: https://www.rollitup.org/marijuana-plant-problems/158144-never-ending-abuse-phosphorous-bloom.html

It took me awhile to come into agreement with UB's arguments. Part of what convinced me was burning up my plants with Tiger Bloom, and seeing the same thing a million times over on RIU, including yours...

If those plants were mine, I'd water hard with plain water and leave them be for at least a week, probably two, and see if I get fresh, perfect growth at the active growing tips. Those spotted leaves will always be like that.

Kriegs said:

You may very well have spider mites, too, but they're not causing those uniformly-arranged burned leaf points. The damage patches they leave are much more random and more in the soft tissue of the middle of the leaves.

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I thought the damage was inconsistent w/ the pics of spider mites I've seen too. And, someone else just told me the creepies I found are the wrong color for spider mites. They look black or brown to me, but I can't get enough magnification to tell for certain... only that they're zipping around on the paper.

Kriegs said:

Personally, I subscribe to Uncle Ben's theory that "bloom foods" are unhealthy for plants, esp in early flower where there is still a lot of active vegetative growth, too. And, I find Foxfarm stuff really strong, and really acid.

Did you pH-up all those feeds? Hope so -- FF liquids are acid as all get-out. The "feeding schedule" also causes a build-up of excess nutes; it's overkill. You will likely see this problem get worse before it gets better, even if you fix it correctly. It will take time for that excess to work out.

Click to expand...

I did not PH up... in fact, I only tested the water before adding nutes. And, I started using brita filtered tapwater last Sun, which is about 5.5, compared to unfiltered tap water at 8. I'm using PH drops to test, so I assumed the results wouldn't be accurate after adding nutes b/c it's already discolored.


hindsight is 20/20, but I'm really wishing I hadn't switched to filtered water now... seems like I've introduced a variable at the wrong time.

Kriegs said:

Check this out: https://www.rollitup.org/marijuana-plant-problems/158144-never-ending-abuse-phosphorous-bloom.html

It took me awhile to come into agreement with UB's arguments. Part of what convinced me was burning up my plants with Tiger Bloom, and seeing the same thing a million times over on RIU, including yours...

If those plants were mine, I'd water hard with plain water and leave them be for at least a week, probably two, and see if I get fresh, perfect growth at the active growing tips. Those spotted leaves will always be like that.

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thx, I think I'll flush today & wait... guess that'll at least allow me to judge the plant's response more accurately.

That's a PH fluctuation problem. I keep my soil PH at 6.5 and my hydro PH at 5.8. Works great for me. But always add your nutes to the water first, then PH the solution, and then check ppm. Adjusting PH will change the ppm count as well. So PH to optimum number for your medium and test your ppm level last. But those light areas in between leaf veins always present themselves to me when I've drastically adjusted PH all at once or have the PH too acidic.

Northofimjin said:

That's a PH fluctuation problem. I keep my soil PH at 6.5 and my hydro PH at 5.8. Works great for me. But always add your nutes to the water first, then PH the solution, and then check ppm. Adjusting PH will change the ppm count as well. So PH to optimum number for your medium and test your ppm level last. But those light areas in between leaf veins always present themselves to me when I've drastically adjusted PH all at once or have the PH too acidic.

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The original post in this thread was from December of 2009, nearly six years ago...

Let it go!

bunch o quacks - you have weak plants from anything - the orange spots are a response to 20 root causes.....flush the bitch will take care of 10 possibilities...