Grodan Gro-Block GR22 Improved Jumbo 6 x 6 x 4 | Case of 64

What Improved Means on a Grodan Gro-Block GR22

Improved is not a marketing word here, it is a specific change to the fibre. Grodan worked with Wageningen University and growers across North America to redesign the structure and add what they call an advanced wetting agent. The result is that water content and EC sit more evenly across the whole block rather than pooling low and drying high. That uniformity is the whole point of it. A block that wets evenly roots evenly. A root system that has colonised the full volume takes up water and feed from all of it, instead of from a wet corner.

Steering With a Jumbo Stone Wool Block

At 6 x 6 x 4 this is the jumbo, and the volume is what gives you room to steer. Steering means running the block wetter or drier on purpose, to push a plant vegetative or generative. It only works if the substrate responds predictably. That is what even distribution buys. Worth being straight about the trade, though. Steering needs measurement to work. Without water content and EC readings from the block, you are paying for capability you will not use. A plainer block grows the same plant. A case is 64 blocks, wrapped in white foil to keep light off the sides and algae out.

Key Features

• 6 x 6 x 4 jumbo: The large format block, with the volume to hold a plant through flower.
• Case of 64: Wrapped in white foil, which keeps light off the sides and algae down.
• Advanced wetting agent: Grodan's Improved fibre, developed with Wageningen University.
• Even water content: The block wets through rather than pooling low and drying at the top.
• Even EC distribution: Which is what makes a block respond predictably to an irrigation change.
• Built for steering: Run it wetter or drier on purpose to push vegetative or generative.
• Only if you measure: Without water content and EC readings, steering capability goes unused.
• Roots the full volume: Uniform wetting means the root system colonises all of the block.
• Takes a block or plug: Sits above a smaller starter block in a standard propagation chain.

Technical Specifications