My 1st Grow

3 plants look good, but worried about the yellowing and dark spots in plant number 2. Diagnosed the issue on the internet as manganese deficiency. Although I only see it bad on 1 plant right now, after looking at pictures, I can see some early signs on the other plants of this starting to form. Assuming my ph is just getting too high, I dropped the latest feeding down to 6.0, and gave them a gallon each. Hopefully that's all it takes, gonna have to wait and see. Didnt touch lst anymore really, the 3 I lsted kinda bushed out so not bad for a little training, the fourth 1 was done a little earlier in its life, and kinda started to christmas tree, but since the height matches the rest, ill leave it.