I decided to not take my 16x48 intex ultra frame pool down this year for winter. I have read that you are suppose to drain the water 6" below lowest return/skimmer opening, now does that mean below the inlet nozzle that returns the water to the pool from the filter, or do I need to drain the water 6" below the strainer grid nozzle that pulls the water out of the pool to the pump? Thanks!!