Hi all have 10 lowryder plants set up up about 25 days now maybe more. I am using 250 watt hps with a fan. Thwe light is a good distance from the plants, but i have noticed the last week maybe more, that 2 of my plants are yellowing at the end and the leaves at the top are curling up a bit. I am feeding them sensi bloom part A & B. Not sure what else to do. Please help. Thanks you