Too close to light? Nute deficiency?

I agree this is not light burn, I also doubt your light is 1000W, may want to look into the real power draw to confirm what it is. or your driver specifications. drivers will have details on how much wattage they are pulling and you can't lie on that stuff like you can on other light specifics. You need to be using other things other then just big bloom, big bloom is part of a trio feeding system with fox farms and it feeds heavy adjust it by watering it down to the desired EC. Given that is an auto you do not want to be transplanting them in the future and you want to use less feed with them as the root shock can put them into shock and enter flowering earlier. https://www.autoflower.net/forums/threads/med-man-method-feeding-chart-ppm-ec.47856/ This link has a good reference point for feeding autos. I also would not be using 24/0 lighting schedule, plants need sleep, with out it they get weird and things becomes issues that are not normally an issue. 18/6 for autos veg n flower and vegging photoperiods. 12/12 for flowering photoperiods. Last tip, as your growing in soil try not to let the PH get below 6.2, ideally it should hover aorund 6.4-6.5seed to harvest. Flushing soil is not recommended if it is really soil and not potting mix/soil as this stuff is normally soilless. Soil compacts and gets water logged easily when getting overwatered. In short, fix your PH, figure out if it is soil or soilless, upload your lights model of take photos of it to find the correct wattage and get a more balanced feed into the medium for the plants. Good Luck!