Superthrive can be used directly applied to media and roots and/or foliar. It is super concentrated so dont be tempted to add a little extra in hope of doing good. Over used it can deform foliage growth and spikes/blooms.
Good stuff though in moderation. Superthrive and seaweed extract equally get my recommendations.
Did post it prev i think 0.25ml per 2 litre, could be wrong without cross checking, am using seaweed at mo.
Very weak doses of fertilizer for phals whether high nitrogen to support general growth roots and foliage or high phosphorus/potassium for spike/blooming. No need to apply fert if spikes are matured.