Cant figure it out (dry tips, sides, spots on leaves)

[endorflight]

I cannot figure out whats wrong.

The strain is Permanent Marker, 4 weeks into flowering. I currently give 50% strength AN nutes in a HPA system. I messed a lot with the spray times, but it seems that iam somewhere in the right zone now.

I had tried less and more nutrients, with and without cal mag, always to some degree with signs on the leaves that look to me most like potassium deficiency.

EC is currently 1.5. Before that i went as low as 0.6.

 

[Jjgrow420]

What kind of light? What are your temps

 

[Hollatchaboy]

Pic 3, it looks like the leaf serrations are curling up. Is that the case?

 

[cage]

It does look like some potassium deficiency..

How's your source water? And how much you've been using cal-mag?
Too much cal-mag might reduce your potassium intake even if there is enough potassium in the feed.

 

[Nizza]

what light levels are you giving them?

 

[endorflight]

The lights are two HortiOne 600 dimmed to 800 PPFD. Due to stretch and limited ability to move the lights higher (i fixed it now) the plants might have received 1000-1200 PPFD for a few days. And the temps are also relatively high at 25-28 C.

The sides of the leaves are not turning up but the tips are curling down.

My water source is RO water with 0.04 EC. I tried to go without cal mag as it seems to be not necessary with AN, however the informations i collected are still unclear. Iam using AN conisseur line, basically with all products.

I increased from 25% to 50% nutrient strength, then got more clear calcium deficiency and added cal mag, after that the burn or potassium deficiency seems to increase/return. The cal mag i added was about 0.2-0.3 EC.

 

[cage]

The lights are two HortiOne 600 dimmed to 800 PPFD. Due to stretch and limited ability to move the lights higher (i fixed it now) the plants might have received 1000-1200 PPFD for a few days. And the temps are also relatively high at 25-28 C.

The sides of the leaves are not turning up but the tips are curling down.

My water source is RO water with 0.04 EC. I tried to go without cal mag as it seems to be not necessary with AN, however the informations i collected are still unclear. Iam using AN conisseur line, basically with all products.

I increased from 25% to 50% nutrient strength, then got more clear calcium deficiency and added cal mag, after that the burn or potassium deficiency seems to increase/return. The cal mag i added was about 0.2-0.3 EC.

1:1 ratio of the part A and B seems to have pretty good balance on the K-Cal-Mag.
Around 4 : 1 : 0,3 ratio for K:Ca:Mg.

With this I wouldn't add any extra Cal-Mag.

Temps and PPFD's has been on the upper end, but should be manageble

 

[endorflight]

I reduced the nutrient strength again to 25% without the cal mag.

PH is at 5.8 and EC at 0.84.

I just dont understand the dynamics of nutrient uptake in high pressure aeroponics. I currently spray 3 seconds, with 180 seconds pause. If i spray so little wouldnt i have to increase the nutrient strength instead of running it so low? I dont get it, i even wonder that the plants survive at all with so little water.

Could also be that my problem comes from overwatering/underwatering.

As far as i can calculate it, i feed 4.7 L / 1.2 gal per plant per day.

 

[DudeTheDevin]

What is your RH? 25-28c temps should be perfect unless RH is below 50%.

Other thing you might try is to raise your PH to 6.0-6.1 so it can absorb different nutes better.