I have found that MG can very easily burn your plant. MG has all kinds of fertilizers available. The one I have heard works ok on this is the patio food MG. Too much N for flowering I think. I have been doing experiments with various ferts. MG was one of the first to get tossed out. I was using it at a 1/4 dose and still had burn. This stuff just does not like it. Look around for Fox Farms fertilizers. They are made for this stuff. I have also had some success with a California brand 'Hawaiian Bud & Bloom'.