I'm going to slow the flow down to 15 gallons a minute. That should get me around 6 hrs to drain. Now I'm reading a section in hydrostatic lift, and why Johnny homeowner should not drain his pool, Ok so there's a valve by the drain that I need to open to release water that could be trapped under the pool,if there is water under there and you don't open the valve the pool will float up causing major damage to the concrete patio surrounding the pool as well as ruin the pool shell itself, Bottom line is cost a pool contractor wants 2800 to resurface my pool, when I can get all the supplies I need for under 400.