Sour Diesel 4th wk into flowering

question tips turnig yellow..anyone know why

How much have you been feeding?

I mixed blood meal into the soil...

don't worry too much. sour d yellows out quite a bit. obviously, if early on, you have one of many element deficiencies, but basically it yellows toward later weeks in flowering. try to stay on top of picking the yellows out later on. sour d is an interesting strain. i generally go 11 weeks (including flush) the problem with a longer strain, and the reason you get false seed pods, or even the possible occasional seed, is because when the plant goes that long, it senses it is near the end of its life and tries to hermi or male out to keep it's species alive. good luck, it's nothing to worry about early on. sour d likes high temps (up to 85 degrees comfortably, especially with co2) make sure to feed it the respected amount of nutes. likes to go a bit higher with the nitrogen and phosphorus.