my plants leaves are drying up curling inwards and turning browny yellow, would this be calmag deficiency or potassium or maybe even a toxicity??, first time grower so unsure
It looks like you have a build up of nitrogen. You may have been feeding to much N when they went into flower. Give the plants a good flush with ph water. Then when it comes to feeding go back to your bloom nutrient at half dose, see if that doesn't cause any problems before upping to full strength.