Hey there. I have a plant that is showing some sort of deficiency or multiple problems and I am thinking it might mainly be a calcium magnesium deficiency. Most of my plants have symptoms but one is effected much worst than the rest. All plants are being vegged. They are about 3 months old and have been having symptoms of a deficiency for a while now. I haven't made a calendar for the feeding schedule which was stupid i know, and the soil i transplanted them into was not amended. I fed them solely Fox Farm's Grow Big for a month or a month and a half since they germinated. since then I have switched the nutrients to the Advanced Nutrients with the base nutes as MicroGrowBloom and B-52 and Botanicare's Cal Mag. For the first two initial nutrient dressings of the Advanced nutes and Botanicare Cal Mag I also added Advcanced Nutrient's Voodoo juice. The I have been mixing 2 tablespoons of the each of the trio parts of the Micro Grow Bloom nutrients to 4 gallons of water, 1 tablespoon of the B-52, and when I fed them voodoo juice I put one tablespoon to 4 gallons of water as well. I put 4 teaspoons of Cal Mag per 4 gallons of water. The water I have fed them has always been super cold hose water that I used, and its about 50 ppm before anything is added. Since I never made a proper feeding chart schedule for them I have probably fed them anywhere from every 6-9 days and the soil has always been bone dry. I water quickly and full saturation of the pots doesn't really happen before the runoff comes out. Pots are five gal industrial buckets i got from home depot. I've used the General Hydroponics PH Up and Down and the green testing solution with the pipette and tiny beaker for testing the ph and its been around 5.5 to 6.5 i think. The problem has been yellowing and brown spots on the lowest growth at first and now the top leafs are starting to get yellow in places and some brown rust spots. The stems have turned somewhat purple. The Advcanced Nutrients don't rely on PH to be absorbed by the plants so i am thinking the problem is either underfeeding, nutrient build up in the soil or a cal mag problem. Thank you for taking the time to read this and i would really appreciate anyones feedback. Ill post a few pics I took of the worst plant.