Looks to me like the plants on the right are suffering/recovering from the ph issue. (paleness, the 'claw' deformed leaf fingers at their base)

Do you by chance move those bags around, or do you take care not to disturb the roots?

Is there proper drainage? How much water and how often?

Beyond these questions, filling-out the troubleshooting form is your best bet for a complete analysis. (link is in my signature)

Mg is rarely the solution. It is good at masking real symptoms and can damage your ladies, though. epsom-salts-not-miracle-cure-thread.html
Rusty Trichome Reviewed by Rusty Trichome on . 1st time grower, Mg suspected what cause, nutes? Hi all, Starting off with 1st post and already asking questions, I am sure people on the site have experience and are nice to answer this. 1st time grower soil : peat moss and perlite. Its called Light Mix from Plagron Water: From the well 6.1 pH run off water is 6.2 pH. both measured with Essential PH meter- Hydrogarden Essential pH Meter: Basement Lighting Hydroponics and Plant Grow Lights Watering when top 2 inches are dry ( every 4 days about ) Nutrients - Algae Grow from Rating: 5