advice for anyone doing an auto first time in a small environment on a budget, 6.5ph is optimal and will give it best results fastest (but autos only). Nutrients ive found 5ml per 500ml is best and each plant gets atleast 250ml more if needed. Its better to let them be a bit warmer than colder and the ph is better higher than lower if it has to be either way.. And keep giving them nutrients constantly throughout grow. Going to move to wardrobe soon with an extra 100w led aiming for 85g minimum 150g im laughing hope I can achieve that.
@TheGanjaMan, Spot on with the LED! The closer the better with a 100w LED as long as its not to hot.
Could you explain the type of yellowing you are seeing? Most cases of Yellowing this early are due to Nitrogen deficiency, Nutrient burn, or PH fluctuations. If It is excess nutrients causing the problems you can just flush the plants with plain PHed water for a few day before starting them back on a reduced nutrient schedule.
Here is a handy guide to help identify some problems that occur!
http://loudclouds.co/wp-content/uploads/2016/07/marijuana-deficiency-chart-jorge-cervantes.jpg