Started maintaining my own pool. Previously had a pool guy and as you can see, doesnt look like he was doing much of maintaining based on my test numbers. CYA is currently at 140. we have a drought danger in California, so draining and refilling the pool is frowned upon. Bought this new product from Bio Active to reduce CYA levels. One pack treats up to 25,000 gallons. Its safe to drop in the entire pack into the skimmer. I've seen price ranges from 41.99 - 59.99 for this stuff. Test results have shown 150ppm CYA levels to drop to 70ppm within a week. Product indicates it will not harm other parameters of the pool chemistry. I'll post up the results in a week.