LECA Clay balls for hydroponics or soil mix. I use these in the bottoms of all my planters for aeration and drainage. I also mix them 50/50 in my soil mix for my plants since they are chemically inert and provide structure for the roots.
1 L for $5
2 L for $9( compare to $15 on Amazon)
10 L for $25
30 L for $55
More available upon request.
