The pic looks like theres a N deficiency which would be sorted by a mild nuterient solution... however without knowing the ph I wouldn't add anything.

You're using promix which should contain enough nutrients to sustain the plant for a while. How old is the plant? If the ph is out, the nutrients might be in the soil but unavailable to the plant as they are locked out.
Wobster Reviewed by Wobster on . Drooping leaves, Yellow fans. E-indoor or outdoor - Indoor E-soil, soilless, coco, aero, or hydroponic - Soil CSL-Soil type/brand - ProMix Bx, and Perlite - 2:1 SCL-Anything you have added to the soil - nope SCLR-Soil or slab runoff pH - unknown E-Water source - tap E-Source water pH - unknown E-Age of plant - Clipped a month ago, been in soil for 2-3 weeks E-Type of fertilizer - none E-Rate of application - na Rating: 5