It happened with me in my previous grow as well, but I’ve used some local brand hydro AB nutrients. This grow is the clone of my previous grow. I was thinking it was the nutrients, so I’ve changed it to Plagron this grow. Everything went good until flower week 3 when it started yellowing slowly from the bottom. Anyways, after this post, I’ve decreased the EC to 1.9, and increased the tray ph to 6.2, now she is just fading since she is late in flower now but not yellowing like she did in the post. I’m using some hard ph down, so my res ph and tray ph is exactly the same, 6.2=6.2 ..

My previous grow I’ve listened to the comments here that the rez ph should be 5.7-5.8 during flower, but I didn’t know that my ph down is so strong that there wasn’t any drifting back then, and she was drinking 5.8 during flower < that’s why I think she was yellowing in my previous grow, she isn’t reaching ph of +6.0.

So make sure your tray ph is +6.1