Magnesium deficiency will exhibit a yellowing which may turn brown and interveinal chlorosis beginning in the older leaves. The older leaves will be the first to develop interveinal chlorosis. Starting at leaf margin or tip and progressing inward between the veins. the leaves curl upwards like they're praying The tips may also twist. i think, not sure though. and i did not recomend epsom salts. i asked for pics and asked about the water change