I can see leaves!

At least, I can see in the shallow end where some of them are are. I've been sustaining 15-20ppm FC, and it's starting to pay off. I can now run the filter with a couple scoops DE in it for an hour or more between backwashes, which is progress!

I accidentally bought Muriatic acid at the pool shop instead of Cyanuric, and can't return it since the bottles aren't sealed. The woman at the pool store said I could use it to clean the element in the filter (Hayward DE4820) - is this wise?

Thanks,
Mark