N-Tox? Keep going or restart?

[AutoCrux]

Hi Growers,

Problem: new growth leafs curling down, ldark green tips.
Medium/grow method: 50% Plagron Light, 45% Perlite, 5%Hydro Pebbles, direct from seed. Soil reused from previous (photo fem - no auto) grow, refreshed with1/3 of recommended silicium flash and some Mykotrex
Feed: and supplements used: Biotabs / Autopots water only schema. 3 Tabs in each pot as per guide.
water source: Autopot. Tap Water. No Ph Adjustments
Strain/age: Mephisto Apollo Haze and Mephisto Piggy Parmesan. 28 days from sprout.
light used: 2x Sanlight EVO 3-60. DLI around 27
Climate: 24.1°C, 61,7%rh, VPD around ~ 1.00
Additional info: Left plant is Mephistos Wedding in same soil, no sings on curled down leafs, only affecting middle (Piggy Parmesan) and right plant (Apollo Haze). The Apollo Haze shows the most severe curl downs and very dark green tips. My previous grow (normal photo periodic strain) in the same soil composition was perfectly fine, with no such problems. I did one top water phase with humic acids and one full dryback.

I am at a loss here, are these really signs of nitrogen toxicity? Will they grow out of it? Should i restart with a fresh soil mix for the Apollo Haze (not sure about the Piggy, she looks a bit more healthy still)

from Left to right: Mephistos Wedding (seems fine), Piggy Parmesan (curl down, lighter tips), Apollo Haze (curl down, dark tips)

Apollo Haze:

Piggy Parmesan:

Cheers
AutoCrux

 

[Lil Dab]

Yes that looks like too much N not a total loss just don’t feed anymore for now just plain water for a while

 

[Frankthetank]

one full dryback.

This….don’t do this. Here’s what happens…. As the water dissipates, the feed that’s left in the medium becomes concentrated….causing issues for more sensitive plants/strains. It’s probably what happened here I’m guessing. Just keep a steady pace, water consistently. Just adjust your watering schedule back to normal and you should be fine…

 

[AutoCrux]

This….don’t do this. Here’s what happens…. As the water dissipates, the feed that’s left in the medium becomes concentrated….causing issues for more sensitive plants/strains. It’s probably what happened here I’m guessing. Just keep a steady pace, water consistently. Just adjust your watering schedule back to normal and you should be fine…

I am using Biotabs, this is basically an organic grow. The dryback may hurt the active/living soil biology, true, which is in fact the one reason this is not recommended to do but there shouldnt be any major nute build-up due to this from what i learned, also not from a single one. Sorry maybe i am mistaken with this No water "schedule" here, i am using Autopots and the system is back online after the dry back. EDIT: Also, the dryback was done after the N-Tox signs started, it was a recommendation from another grower EDIT2: Phrasing

 

[Lil Dab]

Just plain water no heavy drybacks keep the soil happy and they’ll grow out of it