pICCIES!!!!! your description is very detailed, but a pic always helps to define the problem.

if its overwatering, the problem will start from the base of the plant and move upwards and will act the exact same as if you were to stop watering it
klondike_bar Reviewed by klondike_bar on . Does this sound like over watering? Hello all, I have two plants on a NFT table 4ftx2ft,in large rockwool cubes.The pump moves 150L/H and is on constant as this is what ive read.Is this too much? I ask because the bottom leaves have started to get brown spots,gone soft and look wilted,some of the new growth also looks twisted.The plants have been on the tray 16 days on 18/6,being fed canna vega A+B at 1100ppm adding h2o2 every 3 days at a rate of 1ml per litre.600watt hps,fans blowing through and over the tops of the plants.I Rating: 5