Hey Sprocket, is Cyanuric Acid (Stabilizer) what you are referring to as Conditioner?... and I think your alkalinity level is important whether or not you have a vinyl or concrete pool, maybe what you are referring to is Calcium, which is needed for a concrete pool but is not as important in a vinyl pool... and based on your Conditioner (stab?) level of 30, an FC level of 20 seems more like a shock level, I think you should be down in the 3-5ppm of FC, maybe someone else can chime in here on those numbers...