E-indoor or outdoor - indoor E-soil, soilless, coco, aero, or hydroponic - soil E-specific medium - 30% top soil, 30% MG organic, 40% Perlite SCLR-Soil or slab runoff pH - 6.8 E-Water source - Steam distilled water with 5-10ml Calmag per gallon E-Source water pH - 6.4 E-Age of plant - 5 weeks E-Type of fertilizer - Flora Nova Grow E-Rate of application - every other watering E-Lighting source and distance from plant - CFL 5700K ~150Watt eq. 6 inches E-Air temperature - 72-82 E-Air % Relative humidity - 27-37% E-Lighting schedule - 19/5 E-Type of ventilation your room has - vent to outside, circ fan I've got 4 plants going and 2 (which appear to be a different strain) have started curling up and turning darkish and look terrible. I have flushed 3 times now (2 days apart). The other strain is doing great, which I believe in NL. This could be diesel or some blueberry cross, not sure. All bagseed. Any idea what this could be. I thought it might be heat stress so the lights have been moved away, but it's gotten worse since then. Thought humidity, but that's been adjusted and it's around 32-41% now... Any ideas?
Check out the stickies there are a bunch of charts talking about the causes of leaves curling up or down.
Its looks like either a magnesium or zinc deficiency, or Ph fluctuation. Your Ph sounds like it has been relatively stable, and you have already flushed, so good there. Try adding a 1/2 teaspoon per gallon of epsom salts next time you water. The epsom salts will help bump up the magnesium levels, and may bring it out of a lockup. Keep an eye on the Ph, because magnesium and zinc deficiencies often occur together due to Ph that gets too high.