How do you determine each time how long the process goes for? How do you know when you've exchanged enough water to suit your CYA level?I've been replacing the water in my IG pool for the past 5 days to bring my CYA down significantly. Per PoolMath, I had to replace 78% of my water, or approximately 24,000 gallons.
Since the new water is much cooler than the water in my pool, I ended up adding water in the deep end and pumping water out on the shallow end (with the pump sitting on the top step). It worked out quite well and was automatic once I got the inflow to match the outflow.