I have a 4 x 8 tray with several strains in it. One plant has very bad leaf curl and the rest are fine (even the others that are the same strain).

System:
1000 watt hps (bulbs need replaced) air cooled (can touch the glass cover)
Botanicare Nutrients (PBP B, Liquid K, CalMag, Aqua shield, dash hydroplex)
PPM 1500 ph 5.8 (PPM up from 1350 this res change...yesterday)
Used ZHO and Voodoo at start
Temps and Humidity stable using Sentinel EVC2 (68-88 and less than 55%)
1 gallon smart pots with rockwool croutons. The pots are moist.
Flood once daily
lots of circulation fans
CO2 on a timer

It only effects the top leaves so I thought maybe they are too close to the light but the lights are cool and some leaves 24 inches away are doing it and others 18 inches away are not. The other plants off this strain are in the same tray but under a different light (that is shot...will be replaced this week) so maybe they would be doing it to if they were receiving more light?
Most unusual is it just one plant. You can see healthy leaves in the background

The only thing that has happened in the last 48 hours that was unusual was 1) I opened the door in the dark cycle (2 hours after lights went off) for 5 seconds 2 days ago and 2) The flood pump was disconnected and they missed a day of watering 1 day ago (got water last night) which meant they got an extra flood. But once again all these plants have the EXACT same treatment.

Any Ideas...crazy or otherwise...would be great.
My plan is to do nothing and think positive. I think its an underestimated technique.:thumbsup:
bioguy Reviewed by bioguy on . One plant in tray with aggressive leaf curling?!?!?!? I have a 4 x 8 tray with several strains in it. One plant has very bad leaf curl and the rest are fine (even the others that are the same strain). System: 1000 watt hps (bulbs need replaced) air cooled (can touch the glass cover) Botanicare Nutrients (PBP B, Liquid K, CalMag, Aqua shield, dash hydroplex) PPM 1500 ph 5.8 (PPM up from 1350 this res change...yesterday) Used ZHO and Voodoo at start Temps and Humidity stable using Sentinel EVC2 (68-88 and less than 55%) 1 gallon smart Rating: 5