Hi there, just asking the doctors for a quick checkup on some plants. They do have some worrying burnt leave tips and I´d be grateful for any input. Feel free to solve any or all of the questions below, also general tips are welcome, this is my first indoor grow in a while, first one under LEDs. The intention is to do a rather low cost organic grow, with no chemicals involved if possible, although I could contemplate other solutions if necessary. So far I´ve spent less than 200 USD on all the equipment, gear and seeds. The specs: Space: 50cm wide x 1m long x 1,7m tall closet. Strains: 4 Master Kush, feminized (White Label seeds), 1 jamaican import weed, regular (no seed bank). Light: Viparspectra 450W LED. First week distance to the plants was around 15 inches, later went up 20. Soil: POKON Bio (will change to something else soon) Pot size: more or less 1 gallon except for the jamaican. Will transplant to 11 litres - 3 gals a week or so before switching to 12/12. Germination date: between the 10th and the 15th of February. Temperature and humidity: Rather uncontrolled - no thermometer/ higrometer yet - . I live in a very wet area. Its winter so despite the central heating temperatures have been falling to 16 celsius at night. Around the day, when lights are on I can tell its not crazy hot in there. House stays between 16 to 24 celsius. Water and feeding: Tap water, 36 or more hours of resting for getting rid of chlorine. PH has been ranging between 5.8 to 6.8 (aprox). Using color drops to test PH and lemon juice or apple vinegar to lower it. First 10 days only water, then one watering with a homemade lentils sprout root juice (for the auxines and other elements, I read) and two waterings with organic blackstrap molasses (1 tbsp diluted in about 1.5 gallons of water). On the last watering, I mixed about 2ml of Biobizz Grow in about 1.6 gallons of water, plus some more homemade lentils sprout root juice (about 1/3rd of the recommended dose). Various mistakes: I tried a different soil composition with one of the Master Kush. She has about 30% perlite, the rest the usual 10%. She was the first seed to sprout, but her growth has been much slower than the rest. One of the bigger Master Kush had a couple of her leaves burnt by an anti insect spray that I clumsily applied to the fan for spreading around the growroom. I thought that being an organic product meant for humans, nothing bad could really happen, however later on I read it contains alcohol and well thats what happened.Rinsed with clean water, not using it again obviously. The questions: 1. What are those burnt edges on the leaves? Not the one that was burnt by the mosquito spray, but the others. 2. Might it be caused by the feeding scheme? Anything I should change? 3. How long should I wait before moving to 12/12? I feel they are growing quite slow, and having seen other bushy Kush types I´m afraid they will keep on being slow in the next weeks. My space is rather narrow, although kinda tall... would it be worth it to let them veg for 3-6 more weeks or shall I just go for a faster growing genetic next time and start flowering these ones lets say 1-2 weeks from now, after transplanting to 3gal containers? Any other input is much appreciated. Here you have the photos.