Growers Edge® Block Covers 6in (40/Pack) RO Water System They are very safe and

They are very safe and easy to operate

The Active Aqua line of premium white reservoirs and covers offers features that rival the competition at value prices

coco blends

General Hydroponics® FloraNova Bloom® 4 - 8 - 7

Growers Edge® Block Covers 6in (40/Pack) RO Water System They are very safe andGrower's Edge Block Covers block light from reaching the growing media. This helps to reduce algae and pest problems in Rockwool and other growing media. Easily set up the covers by placing the white side up and using a small object, like a toothpick, to hold the cover in place. Each package of Grower's Edge Block Covers contains 40 covers.