Help: potential over fertilisation or over waterning

sprayed them? plants feed through the roots. foliar sprays are a tool used in reaction to a problem, but should not rely on daily or repetitive sprays to provide basic nutrients to your plant. as hard water clogs up appliances and such it will clog up stomata, which brings in a factor far more limiting than fertilizer -- CO2. Maximizing CO2 intake far exceeds the importance of any OCD-based need to foliar feed your plants. i'm not going to answer directly. i'm jsut going to explain better watering habits and you can apply some independent thought to eliminate it as a possibility. i can't tell if that is coco or a soil substrate soil - Water entirety. A little runoff is fine to ensure you don't leave dry pockets in the soil. Wait for top 1/2-1" to dry and repeat. Simple. coco or any soilless substrate - fertilize at 1.3-1.5EC every single irrigation and religiously get 10% or more runoff. Coco holds less water, so the trigger to repeat is a bit different. Once that top layer starts to change colors, it's ready. Let it dry superficially or you'll get weird shit growing on the top over time. easy peasy.. can't over water doing this. You look to have enough perite, so waterlogging roots should not occur while doing this unless you run water through it for 15minutes, lol. common sense applies. so, if you deviate from that in major ways, could be part of the problem. simply stop doing what you are doing and do this (the above). Maybe a bit less light? looks like the nodes at the top of a couple of those are stacked on top of each other.. if very short internodes, that's another sign of too much light. on one plant looks like 3 sets of fan leaves all originating from a very short length of stem. there's some sort of imbalance but if watering habits are off, get that straight fora week or two and continue observing... if it doesn't take a nosedive let the better watering habits have time to have their effect and re-assess.. if it does nosedive, consult a leaf chart and make a best-guess adjustment to formula. diagnosing from leaf symptoms is a bit of a guessing game. some things are way more obvious than others but there are seveal moving parts and potential false-positives abound (ph or nute lockout related etc) whehter you are soil or soilless will make a big difference on those suggestions.