1st grow all auto

mine was doing the exact same thing last week! there starting to recover now. I added the cal mag I finally got along with a little Epsom salt and it seem to be what help it. I'm still not sure what it was but looked just like that. on this plant symptom chart it looked like a cal mag def but still till now im not sure because I tried several different thing from lighting to thinking maybe even root rot with mine. Hope you find the answer tho! that be cool for next time we see this, It really affected my growth :/

Those leaves look like they are just old and faded. Since they are all at the bottom, attribute it to old leaves. If you start seeing any other issues then its time to worry a bit more. Purple stems don't have to be a nitrogen deficiency. It can be, but a lot of strains have purple stems. Most of the potting soils have a lot of nutes in them already. And you are feeding nutrients that have nitrogen, magnesium, and calcium in them. You shouldn't have a deficiency. The only other thought I have about your feeding is to look at the ingredients on your bottles. I found out I was giving a lot of nitrogen to my plant when she really didn't need it anymore. Some of these nutrient lines double up so you end up giving double doses when you don't need it. Overall, your plants look great! If you are not testing your water and run off water then I would start doing that. Keep track of the numbers. Otherwise, twist one up and listen to some music with your girls!!😎😛

Coming along nicely, they are starting to put on some nice weight ;)

They are looking really nice this week! Include a few photos of the yellowing leaves. That will give other growers the chance to help out. It could be a reaction to the increase in nutes. If you are over feeding then you will start to see other problems. New growth will be effected as well.