Vexatious yellowing on this Northern Lights Auto...Can't seem to shake.

Hey all,
Any help here would be great. This is my first grow (Autos unfortunately).
Details:
-Auto (feminized) Northern Lights.
-Tent/Indoor grow, soil, HLG225 + a couple 32w cheapos on the sides
-Well Water (PPM 215-225ish), Watering adjusted to 6.5pH
-Feed: GH Flora trio at about 1/3rd rate (I mix then I 'water down' until the total PPM is 550ish). I've applied a bit of Cal/Mag here and there, but I don't think it's necessary with a PPM over 200 out of the tap?
-Schedule is Feed/wait/wait/feed to reach dry down about an inch. No current signs of overwater. Watering/feeding to run-off.
-Currently in the 4th week of flower.

The other plants in this grow (all autos) are another NL, one Tangerine Dream, one Blueberry. All others are a nice healthy green. The odd thing is that this NL is also the tallest of all of them (stunted from earlier first timer abuse in seedling stage) with the best looking bud development.

I've tried to beef up the feeding, which gave me minor leave burn and not much else. Thoughts and feelings here? Is this plant just a bit of a bitch and it'll just be that way? Any corrective actions you can think of?

Help this poor noob out!

Leaves look like they're curling up. What have your temps been? Consider heat stress.

I had a problem with overwatering. My top inch of soil would be dry, but I found out later because of my soil that the bottom/middle soil was still wet. The picking up the pot and waiting for it to be light method is far superior. Is all the soil the same? Are all the plants the same age? You may want to consider letting it dry out a bit more.

jfarrismu said:

Leaves look like they're curling up. What have your temps been? Consider heat stress.

I had a problem with overwatering. My top inch of soil would be dry, but I found out later because of my soil that the bottom/middle soil was still wet. The picking up the pot and waiting for it to be light method is far superior. Is all the soil the same? Are all the plants the same age? You may want to consider letting it dry out a bit more.

Click to expand...

Thanks for your reply. It's an indoor grow and temps in the tent have not been above 82f in the past few weeks. Someone suggested light stress and possibly too much 'wind' so I've adjusted those things accordingly. I've been watering every 3 to 4 days and digging down deeper than an inch or so, and the plants don't show any signs of drooping (I did overwater early on and they did droop then, but that was back in late July).

In the meantime from posting this, I've done a few things. Since those pictures were taken on feed day and I didn't get a good run-off sample, I did gather some runoff about 4 hours afterwards that was partially evaporated already. It read super high in EC/PPM (up past 2500, but again it was water that had had time to evaporate a bit so not terribly accurate). So being that the soil was already wet from the feed, I just took it outside and poured about 4 gallons of water through it and brought the PPM down to somewhere around 330 (.66 EC). I did get some nutrients in on the backside of the flush because obviously there's some deficiency going on from what I assume is lock out.

Quick update. I think things have stabilized and are looking better and I've made some adjustments in the tent. I did give a water/semi-flush to my other three plants, and this lil NL (NL#1 in my grow) is looking better. I did snip or pull any of the leaves at the bottom that went true-yellow, but the rest have started to darken a bit. Obviously this one has been through a bit, given it's scarring.







I also did some grow-room adjustments. Lights are hitting the bud-tops at about 43DLI now, and I've automated the fans (I think they were too strong and on 24/7. Now the two fans are on opposite 1-hour on/off cycles with a 10 minute overlap (that means sometimes they're both off for 10min and sometimes both on for 10min). I added a third 6" oscillating clip fan above that is really mild and is on 3-hour on/off cycles. Hopefully this will help with the canoeing as well.