Island requirements are: 12"" Planter - 1 Gallon ; 16"" Planter - 2.5 Gallons ; 20"" Planter - 6 Gallons ; 24"" Planter - 8 Gallons
- Blend of calcinied clay and potting soil mix.
- Provides the right buoyancy for island planters and acts to absorb nutrients from the pond water.