1st: my english is very poor, all my apologiz all the informatation: NFT system air in: 100m3/h air out: 400m3/h light: cool tube 400w food: ghe flora serie space: 120x60cm ph: 5,5 EC: 1,5 light is 12/12 since the 5 of june My problem: some part of the plant grow yellow... and i dont know the worlds in english, so, the picure:
It's either a lack of Nitrogen or a lack of Iron. here is what I do when my plants have deficiencies. I flush them the next two waterings with just water. On the third watering I water with all of my nutrients again but at 75% strength instead of 100%. Also if you are watering with straight tap water, let it sit out for 24 hours. This will allow for all of the chlorine in the water to evaporate into the air. Hope this helped.