Grodan Improved Gro-Slab - (36x6x3) - Bag

What a Single Grodan Improved Gro-Slab Gives You

The slab measures 36 x 6 x 3 in, which is 91.4 x 15.2 x 7.6 cm, and arrives in its printed foil. Fiber runs vertically through the wool. That orientation moves water down and out rather than sideways. The slab drains at a predictable rate instead of holding a wet band through the middle. The Improved line is built with an advanced wetting agent and a reworked wool structure. In practice water content and EC sit at the same level at both ends of the slab. That evenness is the whole basis of steering a crop by irrigation. The wool itself is completely inert. It binds no nutrients, so the feed you mix is the feed the root sees, with no initial flush needed. Resaturation after a dryback is quick, which is what lets a grower run a tighter wet-dry swing without stranding the far end dry. The SKU for this single is 320562-S, against Grodan item 320562 for the bagged bundle. This size comes twelve slabs to a bundle.

Wetting and Cutting Rockwool Slabs Before the Block Goes On

Full saturation before planting is not optional on stone wool. Fill with nutrient solution until the bag stands taut at the seams, then leave it a minimum of thirty minutes. Then cut a drainage slit across the lowest point, under the seam, and keep the blade off the wool while you are cutting the foil. Plant holes get cut to match the block you are transplanting, not oversized. An oversized hole leaves an air gap where roots stall at the join. Three plants to a slab is the common layout at this width, and two works where the canopy wants more room. Set a well-rooted block so its base is in contact with the slab surface, then press it down gently rather than forcing it. One or two drip stakes go in per plant hole, and they must not be pushed all the way through. A stake through the base drains irrigation straight to the floor and the slab never reaches content. The limit of a single slab is that it is a trial unit. Treat it as the low-risk way to find out whether a layout works before committing a bench to it.

Key Features

• 36 x 6 x 3 in slab: A 91.4 cm length that sits along a standard bench run without cutting.
• Vertical fiber: Moves water down and out, giving a dryback you can predict and repeat.
• Advanced wetting agent: Holds water content and EC level end to end, which is what makes irrigation steering work.
• Inert and flush-free: Binds no nutrients, so the mixed feed is what reaches the root with no pre-flush.
• Fast resaturation: Comes back up to content quickly, so a tighter wet-dry swing stays safe.
• Printed foil wrap: Labeled and light-excluding, which keeps algae off the wool surface.

Technical Specifications