need help identifing problem

my plants are developing some sort of defciiency, they were feed 1 week ago with 1/2 strength 5-5-7 feed and have improved slightly. their ph is a little high at 7.5-8. could it be a mg deficiecy or should i just feed again? any help appreciated

If that's the Ph of the soil they're growing in then you've got a problem. The Ph of the soil and that of liquids you water with are two different readings. You want more like 6.5