I think Latewood has it covered. If you use tap water it probably isn't a Mg. deficiency because there is plenty in tap water. More likely the Mag is locked out do to Ph problem. You can buy a ph tester like that one in the pic for under 10 bucks and it will save your grow. You are going to need Ph down and up also.
Jdog7000 Reviewed by Jdog7000 on . how r they? here are a few pics i got today there are a few small yellow spots on the tips and the lights are pretty far i think i mean they're CFL's. Could it be a K or P difficency since i'm in the flowering stage? Rating: 5