Leaf Discoloration - Help Me Pick A Culprit

Hi all,

I've got this growing in a top-fed DWC. I've looked through the stickies and can't figure it out. Here are the most recent changes to the environment for this plant.

1. Foliar fed neem oil. There are no bugs, this is just preventative.

2. PH spiked down accidentally. The PH was 5.0 for as long as it took to rise back to 5.5+. Probably 24 hours.

3. Reservoir change with higher nutrients. I just started week 4 od the schedule I'm on so this is the highest nutrients this plant has ever received. I'll use the PPM tester when I get home. I used about 80% of the manufacturer's recommendation as this strain (grape krush) prefers light nutes. I also added in almost max recommended dose of Calmag for the second week/res change in a row as the plants had a previous deficiency.

Advice from green doctor's?

This leaf is near the bottom of the top third of the plant.

It could just be a reaction to the low ph. Although it was only for a short time, because you are in dwc, you see the affects pretty quick. Is it just on the one leaf? Keep eye on it and if it starts to spread/increase, then you can look at something else. If it doesn't get worse, ph reaction.

Looks like a possible bug problem... Have a good look over the plant for any insect life going on.

Martybutch said:

Looks like a possible bug problem... Have a good look over the plant for any insect life going on.

Click to expand...

I agree -- looks like bug bites to me.

it looks like mites to me, i just killed off a swarm of the little fuckers, mighty wash works i just bought a gallon.

looks like spider mites flip that leaf up you should see little black dots that move spray
with mighty wash leaves top to bottom insides and out then spray pyrthyum spray
around base

I stared and stared at every inch of the plant. I flipped over many of the leaves. I can't see any bugs.

Is watch and wait the best plan?

I'll spray more neem oil on tonight anyway.

You aren't spraying with the lights on are you?

You know what? I recentlyl re-programmed my light schedule. I usually put neem oil on 15 minutes before lights out but on my new schedule that is 6 hours into an 18 hour cycle. Long story short : yes, on Monday I did neem oil that was on the plants for most of a light cycle.

Update: still no signs of bugs and no further discolouration on the leaves.