Rockwool Block Covers, 4'', Pack of 40 PLASTIC BLOCK COVERS Reflect 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

EcoPlus Hydrovescent Air Disc 4 in EcoPlus® Hydrovescent Air Disc® air diffusers are great for aerating or circulating nutrients in your tanks or reservoirs. These air diffusers incorporate suction cup feet to keep your Hydrovescent Air Disc® secured

These great quality Air Stones aerate and add oxygen to the water in your reservoir or grow system. Circulates nutrients into the water and helps to maintain an even water temperature. Use with 3/16 in ID air line

Rely on Active Air non-insulated air ducting with your reflectors, exhaust systems, and other systems. Features Durable construction for lasting performance Dual layer thickness 2 stainless steel clamps included 25' of ducting Can withstand temp