Diagnosing Salt lockup or Light burn?

[MasterChief]

Clones multiple strains: Yesterday was start of week 6

Substrate: Promix
Containers: 1-2gal pots (depending on plant size) Everything was up potted before initiating flowering.

Nutes used with every watering: Liquid Karma, Bio Boost, Pk13/14 (used per canna guidlines), Cannayzm, Rhizotonic, cal-mag, Power flower.
Foliar feed

EC- 2.0-2.2
PH cycled between 6.3-6.5-6.8

Two days ago right before the start of the 6th week noticed what appeared to be light burn on the leaves, some cupping and yellowing on others. Raised the lights a little because the day before the reflectors were cleaned, thought it may have something to do with more intensity.

Next day noticed the state of the plants worsening and suspected salt lockup, began flushing the plants.

Measured Runoff while flushing:
EC- Some plants as High as 2.2, the better the plant looked the lower the EC of the run off was, lowest being somewhere around 0.4-0.6
PH- 6.1

Finished flusing everything else tonight, but noticed some of the gals from yesterday still look like they are getting light burn.

The runoff of the plant in the first picture had an EC reading of 1.0

 

[Seamaiden]

You've got a few things going on, so, in answer to the thread title, yes. I see plants that have been burned by heat/light and by something being off (could be lockout, could be feeding too hot). I grow in coco and I don't like letting my EC get as high as a solid 2, let alone over 2. I keep it in the 1.6-1.8 range when I'm pushing them.

That mix includes nutrients that I don't use, and so am not familiar, and others that I use very judiciously and definitely not with every watering, like Liquid Karma and the P/K product (I use Koolbloom, Big Bud, MOAB). In my opinion it's been a hot mix, there's definitely light burn going on with those pinched leaves, maybe the Mg is either locked out or needs to be bumped up (the older leaf with the interveinal chlorosis), which is something I've had problems balancing with GO CalMag+ at times...

What else..? I could be wrong about the Mg, it could be Ca, I have to go back over the notes. I don't grow in Promix, either, so not familiar with that as a medium.

You did the right thing raising the lights. And now you know to be careful next time.

One last thing, in a situation like this, you can try the quick fix of a foliar feed. For instance, 1/4tsp per gall of Epsom salt may help in this case, if there is a problem with locked out Mg. Don't forget to use something like stylet oil, SM-90, or a few drops of dish soap to help it not bead up.