I just discovered the whole CYA issue. I know I need to replace water to get rid of CYA (it's 150). I was surprised to learn that although I have a pool pump, there's no way to use it to drain water. I need to rent a pump at the cost of about $50/day. I was also told to drain only about half of the water at any time in case there's water below the pool that could cause the empty pool to rise (unlikely where I live in Southern California -- but I'll play it safe). Therefore I may need to keep the pump for 2 or 3 days.

Does anyone know if i can replace water effectively by turning on my filler line and letting water drain out the overflow. Since the water comes in on the surface and the overflow is also on the surface it seems like I might just be losing the new water. Maybe running the filter at the same time would circulate the water? I'd appreciate any information anyone has.

The pool is 17,000 gallons and goes from 3.5' to 8'.

Thanks,

Larry