Phosphorus can be stored by the plant so you need to up the rate of transperation to save her. Up the heat and put a fan on her. Deficiencies of the phosphorus is still a lock up due to the way plants store it I would figure. Even after flushing 10 times the amount water to soil nutes will remain so I would hold off with cranking the numbers. I would feed her under 100ppm of added ions at a constant. If you got a multivapor it will fair better then under a HPS. The MH has more blue light which produces cloroplasts and gives a nice green color. To much yellow and you will be breaking down the cloroplasts to fast for the plant to stablize itself. If a leaf is more then 75% damaged cut it off. Damaged part of the leaf can be trimmed off to. To much cutting will cause stress which will be counter productive aswell.
One love
c