Brown spots on leaves, 13d plant

[tadlawid]

Hello 420 experts,

need your advice on this appearing disease : Nutrient Abuse i think but need to be more precise

I'm going to lower EC from 0.76 to 0.4 to start.
Tap water with corrected Ph and nuts Vaalserberg Garden Element 1.
Air temp is 79 F
Relativ Humidity is too low : 40 %
Water temp is 78 to 80 and my tomorrow goal is to make a diy chiller, i think 'im gonna buy a little fridge like car's models with a heat exchanger plugged inside

Other advices ?



Thanks again