K deficiency?

Hi everyone, I was wondering if my suspicion is correct? Looking at the diagnose your plant guide it seems like a pretty good match. Anyway, I'm running a dtw drip system in coco under a 600 watt hps. I'm using canna a and b, calimagic, pk 13/14, and drip clean. I also use some Moab later on. My PPMs are around 950, using ro water. My ph settles in at 6.3 no matter what I adjust it to. I read somewhere that cannabis likes a slightly higher ph during flower, not sure if that is true. Temps are in the upper 70's. Seems to only affect the lower fan leafs.
Oh, and they are in 3 gallon pots getting fed 4 times a day. I'm running 3 different strains and they all seem to be affected by this, gets worse the later in flower they are.Did a thorough search for any bugs with my 60x and 100x scope, did not find a thing. What do you guys think?

feeding too much too often. why four times a day? I think you've killed them. buy ffof and you shouldn't have to feed much at all.

I like my coco, plants look great other than the lower fan leaves. Don't really want to do back to soil. It's pretty common to feed coco several times a day, you get almost hydro speed. Definitely not overfeeding, no signs of burns on any of the top three quarters of the plant. I know what n toxicity looks like from overfeeding in soil when I was a total noob. I don't believe this is nutrient burn.

I still suspect it's fert poisoning somehow, not necessarily nitrogen.

Sounds like temp burn or overfeeding as for me.

Stop the PK. Its too hot and has caused this nute burn.

I will back off the pk, and see what happens.
Thanks everyone!

Their "feet" are too wet!
Looks like over watering to me!

adding liquids more then once a day and not letting them dry out some more = what you've got!

how long is your watering? coco only needs 2-3 times a day at 15 min each. canna is so clean, i doubt you need the drip clean. it is usually pretty good with cal mag too, so calimagic might be overkill. unless you are not using canna coco.

pk 13 should only be used around week 5 for a week. I suspect the calimagic or drip clean is buffering your solution to be stable at 6.3

My watering is in 2gph drippers they are on just until I
I get slight runoff. I'll cut back the number to three times a day. I'm not using canna coco, can't remember the brand name, the local hydo shop recommend it. It is a mix on coco coir, coco husks or chunks and that porous glass rock.
I was not using the calimagic at first since I thought canna had enough since it's a coco specific nute. I'll cut the calimagic out as well, and see what happens. Thanks everyone!