Grodan Grow-Chunks 2 cu ft Bag, Case of 3. 3/4 in Stone Wool Chunks, 6 cu ft

What Is in a Grodan Grow-Chunks 2 cu ft Case Each bag holds 2 cubic feet of stone wool cut into chunks about 3/4 of an inch square, and the carton holds three bags. That is 6 cubic feet in one shipment, Grodan item 70039, packed three bags to a carton and eight cartons to a pallet. The chunks are the larger cousin of Grodan's Grow-Cubes, spun from molten basalt into the same fibre and then cut coarse. Coarse cut means big air gaps between pieces, and a pot filled with chunks drains fast and stays open at the root zone. Each chunk still holds water inside its fibre the way all stone wool does, so the pot is airy and wet at the same time. The media is inert from the bag. It adds nothing and holds nothing back, which hands the whole feed program to the grower from the first irrigation. Chunks go in a pot on their own, or they go around a block to fill the gap between the block and the pot wall. They mix into coco or soil to open the mix up and add water holding. They also layer over clay pebbles in flood tables and buckets. A net pot of chunks starts a seedling that later drops into an ebb and flow tray, a bucket system or an NFT channel. The material weighs a fraction of what the same volume of potting soil does, so a filled fabric pot is still liftable. The fibre suits recirculating systems from the first drain, with re-saturation that stays even after a dry-back. Nothing in the bag is pre-charged, buffered or amended. It is clean fibre, and it arrives dry. Running Loose Stone Wool Chunks From the First Soak Loose stone wool chunks start the way every Grodan product starts. That is a full saturation in a solution set to pH 5.5 and an EC of 1.5 mS or higher. Soak the chunks in a tub until the bubbles stop, then let the excess drain away rather than squeezing it out. Weigh a handful wet and a handful dry once, so later checks by hand have a reference. Fill pots loosely and never pack the chunks down. Packing closes the air gaps that are the reason for choosing chunks in the first place. Around a block, pour the chunks in and tap the pot on the bench until they settle on their own. Feed with a complete solution from the first watering. Stone wool carries no nutrient, and a chunk-filled pot shows a deficiency within days if the feed is thin. Irrigate to a small run-off and let the pot dry back between cycles. Chunks drain quickly, so the dry-back is faster than in a block. A pot checked by weight in the afternoon tells the grower when the next event is due. Watch the EC in the run-off rather than guessing. A rising number means salts are building in the pot and the feed wants more drain or a lower strength. Keep the top layer covered with a lid, a mulch or the pot's own rim shadow, since bare wet fibre under a lamp grows algae. At the end of the cycle, shake the roots out. The chunks come away clean enough to go to the compost or the garden bed. Store an opened bag dry and closed, and it keeps indefinitely. Key Features Three 2 cu ft bags: 6 cubic feet of stone wool in one carton, Grodan item 70039. 3/4 in chunks: Coarse cut for air gaps between pieces and water inside each one. Inert basalt fibre: Adds nothing and holds nothing back from the feed. Pots, back-fill or blends: Alone in a pot, around a block, or mixed with coco, soil or pebbles. Net pot starts: Seedlings that move on to ebb and flow, buckets or NFT. Light to lift: A fraction of the weight of the same volume of soil. Recirculating ready: Rated for recirculating systems from the first drain. Saturate at pH 5.5: EC 1.5 mS or higher, soak until the bubbles stop. Technical Specifications Specification Value Brand Grodan Item code 70039 Product Grow-Chunks Bag volume 2 cu ft Bags per case 3 Case volume 6 cu ft Cases per pallet 8 Chunk size About 3/4 in Material Stone wool, spun basalt Nutrient charge None, inert Saturation pH 5.5, EC 1.5 mS or higher Uses Pots, back-fill around blocks, media blends, net pot starts