Hydrofarm - Rockwool Block Covers Pack of 40

PLASTIC BLOCK COVERSReflect light to plant leaves, where it’s needed most. Block light from media. Eliminate algae and mildew growth. 40 dual sided block covers per pack. Works great with GRODAN Blocks.

• Block light from media
• Reflect light to plant leaves where it's needed most
• Eliminate algae and mildew growth
• 40 dual-sided block covers per pack