I've been reading this thread as well as others regarding the cyanuric acid curse. My pool has been in service for less than 1 year and the CYA level is already over 100. Not that many pucks have been used.. and the pool is big. I think the pool service company anticipated rain dilution over the winter, which didn't happen. Partly because I kept the pool covered and pumped the water off the cover and partly because there wasnt that much rain. So, I'll have to drain and refill. The water I must use is relativly clean, but not city or well water. It will contain some contaminants including some algae. The strategy is as follows.
1. Shock the pool heavily
2. Turn off all filtration after shock is complete
3. Start adding new water at approx 20 GPM at the bottom of the deep end. Put a diffuser on the hose end to minimize mixing
4. As the water rises, it will flow over the low dam wall and out the drain in the cover well.
5. Because the incoming cold water is dense, it will stay on the bottom and the warmer water will flow out over the cover dam wall.
6. In around 18 hours, about 50 percent of the water will be swapped, with some allowance for mixing
7. Turn on filters, reshock and balance
So, thats the plan. Any thoughts? Thanks.