Grodan Rockwool Granulate Fine 25kg bag with a pile of loose stone wool granulate
Grodan Rockwool Granulate bag of loose stone wool growing media
Grodan Rockwool Granulate Fine 25kg bag with a pile of loose stone wool granulate
Grodan Rockwool Granulate bag of loose stone wool growing media

Rockwool Granulate by Grodan — 25kg Bag of Loose Stone Wool for Pots and Media Blends

GGB25

$249.95
/
Tax included. Shipping calculated at checkout.

Loose, water-absorbing stone wool granulate in a 25kg bag. Use it on its own or blend it through coco and other media for more water holding and air.

Size
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Pairs well with

Grodan Granulate is loose stone wool: the same water-absorbing fibre as Grodan's cubes and slabs, broken up so you can fill pots with it or blend it through other media. This is Grodan's Fine grade, with 3 to 6mm fibres, in a 25kg bag that holds 140 litres compressed and opens up to at least 150 litres. Run it on its own in pots and hydro systems, or mix it into coco and other organic media to hold more water and keep the mix airy. It is inert, so every bit of nutrition comes from your feed. It is also a big, bulky bag, so it ships as freight rather than on our free shipping offer.

Use it straight or blend itGrodan designs granulate to be run on its own or mixed through other media. One bag covers both jobs.
More water and more air in a mixGrodan adds water-absorbing granulate to organic media to lift water holding and keep the blend airy. That is the fix for a coco mix that dries too fast.
Holds its structureStone wool does not rot down or compact like peat or bark, so the mix you set up is the mix you finish with.
Fine grade, 3 to 6mm fibreThe finest of Grodan's three granulate grades, and the densest at up to 160kg per cubic metre.
Inert, so you run the feedNothing in it to feed the plant or break down. Your nutrient solution is the whole program.
150 litres from one bagThe 25kg bale opens up to at least 150 litres of loose media, enough to fill a run of large pots.

Specifications
Brand: Grodan
Product: Granulate, Fine grade
Grodan code: 14556
Material: Water-absorbing stone wool
Fibre length: 3 to 6mm
Bag weight: 25kg
Bag volume: 140L (compressed)
Ready-to-use volume: 150L minimum
Maximum density: 160kg per cubic metre
Use: On its own or as part of a mix

Grower's Tip
  • Break the bale up outdoors or in a well-ventilated space, and wear gloves and a dust mask. Dry stone wool fibres irritate skin, eyes and throats.
  • Wet the granulate down before you work with it. Damp fibres do not float around the room.
  • New stone wool can push pH up, so soak it in pH-adjusted water before planting and check run-off pH over the first few feeds.
  • Grodan does not publish a blend ratio for mixing granulate into coco. Start with a small share, see how the mix drains, and adjust from there.
  • Fine is Grodan's densest granulate. It holds together well, so it suits pots and blends better than open, fast-draining beds.
  • Keep an opened bag closed and dry until you need it.

How To Prepare It
1Open the bag outdoors or in a well-ventilated space, wearing gloves and a dust mask.
2Break up the compressed granulate into a tub or wheelbarrow until it is loose.
3Soak it through with pH-adjusted water or a weak nutrient solution, then let the excess drain off.
4Use it on its own, or mix it through coco or your other media until the blend is even.
5Fill your pots, plant out, and check run-off pH and EC over the first few feeds.

Pairs Well With

Frequently Asked Questions
Is this the Fine or the Medium grade?

Fine. This 25kg bag is Grodan's Fine granulate, with 3 to 6mm fibres. We no longer stock the 20kg Medium bag.

How much media does a 25kg bag make?

At least 150 litres once it is broken up. The bag holds 140 litres compressed.

Can I mix granulate with coco?

Yes. Grodan makes granulate to use on its own or blended with organic media, where it adds water holding and keeps the mix airy.

Does rockwool granulate contain any nutrients?

No. It is inert stone wool, so all nutrition comes from your feed.

Do I need to soak it before use?

Yes. Wet it through with pH-adjusted water before planting, so it is evenly moist and you start from a known pH.

Is stone wool safe to handle?

Yes, with basic care. Loose fibres can irritate skin, eyes and throats, so wear gloves and a dust mask when you break up dry granulate.

Does it qualify for free shipping?

No. It is a big, bulky bag, so it ships as freight, calculated at checkout. We deliver it Australia-wide, Tasmania included.

Fill Your Pots With Grodan Stone Wool

25kg of Fine grade granulate, 150 litres or more once loosened. Ships as freight, calculated at checkout.

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