Hello ! Generally most of the soil are pre fertilized and have enough nutrients for 3 to 4 weeks of vegetative grow. Since you transplants during week 2 you can now start to feed with a nutrient for vegetative growth. I've seen you used a 10-6-6 nutrient : the values age good for vegetative stage so you can feed once every 2 watering ( one with water , one with feeding and repeat ) but the only way to know how much to give to the plant is th buy an Ec/Ppm pen tu check one of these values and know if you feed them too much or not and at that stage I would give them around 0.8 to 1.2 Ec. For the flowering stage you will need a Bloom dedicated nutrient like bio bloom or if you can't go to your local growshop then try to find a nutrient with more Phosphorus (P) and Potassium (K) than your actual, I can't really give you a value as the bloom nutrients formulas are all differents but most are made with more P and K than N. Now concerning the plates , I think that both the plates and plastic bags are retaining water but you have more evaporation thanks to the bag. I also noticed that you were watering a bit too much : 1st ) At that stage no need to water until you see a runoff except in case of extremely dry soil ( require to break the surface ) 2n) On each weeks pictures your soil looks moist and I think the moist is continuous so you should know that cannabis grow better when you settle a dry / wet cycle , that mean you need to wait until the soil get a bit dry to water. To know when to water just lift your pot when it's dry and remember the weight , then water and lift again , now you need to weight until the pot recover the light weight before watering again. I hope it will help you 😁👍