Clorox Pool&Spa Granular D.E. Filter Aid for Swimming Pools, 24 lbs – Walmart.com $10.33

In the Walmart After Christmas Clearance section. Delivery may be restricted to your area.
Clorox Pool&Spa Granular D.E. Filter Aid, 24 lbs:
Removes small particles and metal from pool water
Improves filtration
Pure diatomaceous earth
For D.E. filters and sand filters
https://www.walmart.com/ip/758576665