LED Nitrogen toxicity?

[Ingvar]

Hey guys,

Ran into a strange new issue with my recent harvest and wanted to see if anyone else here had an experience like this.

My current room is half HPS half LED (non-CoB, old school 600w (300w draw) purple LED lights). Starting from about half-way through bloom the plants under my LED lights started clawing down - a nitrogen toxicity issue that I haven't seen in my grows since I was a total newb to this. The plants don't seem to be negatively affected. They look good otherwise (although the final yield is obviously yet unknown).

What's more odd is that I don't really use a lot of nitrogen in bloom. My base NPK is about 1-3-3 in bloom. Even when I cut it down further (like I usually do in last few weeks), it still didn't fix this issue. I'm growing in coco, using GH as base nutes, CalMag+, and AN for supplements (Big Bud & Overdrive). Since this is my first run with LEDs in bloom, I have no clue where this is coming from.

Anyone else have this happen to them? Or at least any thoughts on why this may happen?

 

[CobKits]

if i had to guess lower leaf temps>lower transpiration>nute accumulation?

you sure its Ntox specifically and not just salt buildup?

 

[PSUAGRO.]

watering habits?

 

[Ingvar]

if i had to guess lower leaf temps>lower transpiration>nute accumulation?

you sure its Ntox specifically and not just salt buildup?

I can't say for sure it's not salt buildup, but the plants look just fine otherwise - the buds are almost as big as the plants under the HPS lights. The plants under HPS lights don't have this clawing symptom. All plants get the same feeding & watering schedule.

I do use DripClean (every feeding) as well as Recharge (weekly) for beneficial bacteria to prevent salt buildup / nute lockout.