Yes, I understand the relationship. I had just filled the pool with about 15000 gals of water, and I had closed it with about 60 CYA, so I know that the CYA was probably low. I'll be checking that soon.

Again, my water is sparkly clear it was after just a few hours, I've used the information here for years and have never had a problem. My question was related to 5 year old sand vs. zeo and the use of "Sand Helper," not about the water numbers.

Thanks again, but this thread can probably be closed.