Nute burn or ???

[click]

Hello friends,
I am seeing what appears from my online research to be nutrient burn on one of my ThaiHaze Autos. However, I would love other opinions as I thought I was being conservative with the Veg mix and I do not see it on the other plants (at least not to this extent).
All are running on a 18/6 light schedule.
Light at the highest cola of this plant is 16.9k Lumens
Humidity in the room hovers between 35 and 45%
Temperature peaks around 78F during the day directly below the lights (sensor hanging just below the upper foliage) and is kept above 65F at night via a heater (just visible in the lower left of the "room" pic).
pH of the run-off is a tad high at 7.5. Have been watering with pH 6.5 distilled water (vinegar added) the last few days to try to bring it down gently but so far runoff readings haven't moved.

closeup:


plant:


Here is the location in my grow room. It is the one in the ACE bucket in the right foreground:

[SoOrbudgal]

Did show pics click

[click]

Did show pics click

That is weird. The pics show up for me when I am logged in - but only when I am logged in. I will try editing and uploading the photos again...

[Bowhunterwoody]

Worked that time.

[Bowhunterwoody]

Not sure about drainage into those buckets. If air can't escape water may pool in the bottom of your pots.

[click]

Good thought but it's not a perfect seal. Setup isn't ideal, though. A pain to get to the runoff for draining and measuring.

[Bowhunterwoody]

click a few paper clips in between the pots and the buckets would be enough.

[click]

good suggestion

[dilvish]

Doubtful it is nute burn because the tips usually go yellow or brown and they look white in this pic. try recalibrating your tester and continue on. Remember to feed properly in the veg stage...its a common thing but keep an eye on it and make sure you are watering properly.

[click]

Thanks. Recalibrated my tester (Apera PH60) but still getting the same readings. Immediately after starting this thread, I decided to get a little more aggressive and am watering with a batch pf pH6.0 water. Is coming down now and the plant seems to be recovering (leaves are uncurling). I'll posts a pic below.

[homegrown]

I'd drill 100 holes around each one of those pots...poor drainage no air too roots.

[click]

Drainage seems good. Doesn't take long at all for it to work its way through and start dripping into the buckets and the soil is dry each morning when I water. Point taken on the air, though. The only air it gets is what gets sucked in from the top as the water drains.

[dilvish]

your soil is dry every morning? That's odd based on your room temps. soil in those pots shouldn't be dry by the next day so either your temps are off or you are not watering enough. when you say dry...do you measure using a finger? 1-2 inches deep of topsoil dry in 1 day is a problem

[click]

I just push my finger in about an inch occasionally. Not bone dry but my finger is not wet at all. I don't like testing deeper or more often because the plants roots occupy the entire pot so I am damaging them every time I test. I can feel them breaking as I push my finger in - even at the edges. The soil feels very spongey and springs back when pressed. When I water it flows through quickly - nothing sits on the surface.

[click]

I've been more aggressively bringing the pH down since folks on the forum all seem to agree that correct pH is very important. Started watering with pH6.0 water and it seems to be improving. Leaves are uncurling and latest runoff was at 7.2.

[click]

Also, I will mention in case it is an important clue. My runoff is brown - looks like tea.

[dilvish]

if you are growing in coir that is normal but soil maybe. if it's coir a PH of 6.0 is fine going in. if it's soil it should be 6.5.