Brown spots

Hey there,if the problem is situated in the new growth you have a deficiency of an immobile nutrients,in the the lower part it’s a mobile nutrient But to be honest I think your plants are suffering from multiple problems caused due to the lack of proper nutrients,canna boost and pk 13-14 aren’t nutrients,they are additives to add only after the second week of flower until you start flushing The leafs curling down could be an nitrogen toxicity which is called an nitrogen claw but since your not really feeding nutrients this is almost impossible but those long thin leafs make me think your major problem is ph..I have seen the same growth on a friends plants with very low ph which blocks out nutrients who are important in the flowering stage and could explain the little brow spots on the bigger leafs as an calcium deficiency Looking over your diary I noticed 2 things..the daytime temp is a bit high..try to adjust this with an exhaust fan or if you are already using this an extra inline fan Second thing is your watering Almost 3l/24 h is a huge amount of water for a 11l container..I use also 11l containers but use about 2l every other day..it’s important to get a good wet/dry cycle in your root zone,the roots benefit from the oxygen that can reach the root zone in the dry period..if you keep pouring large amounts of water your risk suffocating your root zone and blocking the nutrients in it I hope this was a bit useful to u Happy growing and stay safe ✌️🌱