curling up and getting pale

[freeride high]

hey guys!
got a problem for you that i havent been able to solve myself, the symptoms dont really add up and id like to get it sorted before i take come clones and put her in flower.
background;
this is my 2nd grow, first time in soilless media.
strain is purple kush from clone.
i started in a pot of coco, then at a couple weeks transplanted into canna coco slab.
this is a closet grow under a 90w ufo led, gen3 if it matters. started on 24 then switched to 18-6.
im using the canna a+b at 60% reccomended and not getting any burn. im also using rhizotonic at 75% reccomended with the occasional foliar feeding of rhizo. im using the cannazyme at 50% reccomended.
im watering with a drip system for 5 mins every 12h using 4gph nozzles moisture levels are perfect imo.
my ph is at 6.5-6 in the tank and comes out of the faucet at 7.5-7 i use a brita filter to filter my water, but have only done that with my latest tank refills.
temps are 90-70, though it is finally starting to cool down.
the closet door is open most of the day, i shut it at night. plenty of ventilation.

i suspect mag def, so i added some epsom salts to the tank and sprinkled a bit on the coco, i also tried a foliar feed of epsom and i dont think it changed much.

 

[Abja Roots]

Usually when I see curling up. I think heat.

If the temps are getting up to 90 that's way too hot in my opinion. One thing I do when temps climb is to reduce nutrient concentration. Since the plants are taking in lots more water to try and cool themselves. Also I don't foliar spray with rhizotonic at all. Maybe when I did it the concentration was too high, but they didn't seem to like it.

It's hard to see in the purple light. If you could take a picture with natural light it would make the color much easier to see.

PH seems a bit high for coco as well. I'm usually between 5.8 - 6.2 Depending on whether I'm flowering or vegging.

I can see what looks like discoloration in the leaves but it's hard to tell exactly what it's doing.

 

[freeride high]

yea sorry there crappy pics, its mostly heathy, its just a few leaves that are curled and very pale. i dont think its starting in the new growth, but its hard to tell.

 

[EvilTwin]

fh,
Mg deficiency doesn't necessarily cause leaf curling. The most prominent sign is lightening between the leaf veins that gives the leaves a striped appearance. Sounds like you went a little bonkers with the epsom salts by administering it three different ways. It's OK to have epsom salts in the res as a maintenance thing but keep it light...maybe 1/4 tsp/gal for now and if you get improvement, then maybe increase it a bit.
ET

 

[freeride high]

i used extremely small amounts, i just hit it 3 ways to see if i can get a change asap.
and it looks like its working, the new growth isnt rolling, and the damaged leaves arent getting any worse.