Can anyone help me please, I'm trying to sort my pH in my media it's a phosphorus deficiency do I need to flush with pH water and adjust nutrient

You never want to flush when using a time release potting soil. The way they work is they release nutrients by slowly dissolving in water. If you flush you will release to many nutrients and burn your roots. Looking at your plant this may already be the case. One of the first signs of nutrient burn is your leaf tips turn brown. Adding phosphorus might not help because to many nutrients can cause nutrient lockout when it will not be absorbed. This is why most growers stay away from slow release media. Your options are either repot in a better medimum and buy nuturents to feed her or try to fix any deficiency with a foliar spray.