I'm lost with this one

What can cause this other than bugs ? I can't find a single bug with my USB scope or loup.

High temps and too much water can cause your leaves to curl in like that, make sure your temps and humidity is ok.

When checking for bugs a common place people forget to look is under the leaves, look for any black specks which could indicate bug poop.

extreme or excessive wind can do it too.

looks like everything is wrong with it, i'd start with ph of the medium then ec if salt nutes. i dont see bugs but my eyes are bad

Letting medium get to dry and not being consistent on watering

Still can't find a single russet even under the 200x. I'm starting to think it could be my ph pen so I ordered a new one. Burned 3 plants because they completely gave up. We'll see what happens with the new ph pen.

You have to be under watering
I run straight well water At 8.1 and never check ph
No burns at all

Green Refuge said:

What can cause this other than bugs ? I can't find a single bug with my USB scope or loup.

Click to expand...

Ph issues

Herb & Suds said:

You have to be under watering
I run straight well water At 8.1 and never check ph
No burns at all

Click to expand...

I use well water too it's usually 5.5-6.0 according to my pen. I can water more on one plant and see how it goes.

farangar said:

High temps and too much water can cause your leaves to curl in like that, make sure your temps and humidity is ok.

When checking for bugs a common place people forget to look is under the leaves, look for any black specks which could indicate bug poop.

Click to expand...

Green Refuge said:

I use well water too it's usually 5.5-6.0 according to my pen. I can water more on one plant and see how it goes.

Click to expand...

Big stress. I think it has more than one thing going on.
Leaf curl is also a sign of fungus, also Heat Stress. There's quite a few causes, unfortunately.

Running with scissors said:

Big stress. I think it has more than one thing going on.
Leaf curl is also a sign of fungus, also Heat Stress. There's quite a few causes, unfortunately.

Click to expand...

I originally thought it was heat stress but I ruled that out. I measure leaf surface temperature at 65-74. My PH pen was off by almost a whole point but I'm still not sure if that was the cause. If things don't improve in the next few days I'm just put them down and start a new batch.

Green Refuge said:

I originally thought it was heat stress but I ruled that out. I measure leaf surface temperature at 65-74. My PH pen was off by almost a whole point but I'm still not sure if that was the cause. If things don't improve in the next few days I'm just put them down and start a new batch.

Click to expand...

I took another look at your pictures.I grow a lot of different stuff inside and outside. I started dabbling with Marijuana last winter. I grow in dirt.
It really looks like a fungus or blight. Generally, fungus is soil related. Water from watering soil splashing on a leaf can start it.

Looks like you splashed nutes on them when lights were on, just my opinion. Ph could be too acidic also. Could be wind burn but l doubt that very much. Drippy watering practices are my bet. Double checked pics and damn lm good! Can tell leaf with middle messed up is from when was tender and cooked from water magnification. Can see the drop in my minds eye.

Running with scissors said:

I took another look at your pictures.I grow a lot of different stuff inside and outside. I started dabbling with Marijuana last winter. I grow in dirt.
It really looks like a fungus or blight. Generally, fungus is soil related. Water from watering soil splashing on a leaf can start it.

Click to expand...

Leaf Septoria.

Dont forget to calibrate and store your ph pen in storage fluid. If you dry store you should calibrate regularily. Love my litmus liquid the best. Never goes out on me. Is from splashed water, watch from here out and see. Was splashed a while back, week or so anyways.