What are MultiGrow Rockwool Cubes made from?
MultiGrow Rockwool Cubes are 75mm x 75mm sterile blocks made from rock mineral wool and bonded with ECOSE®, a formaldehyde-free, plant-based binder. Their natural brown color comes from the ECOSE® binder, not dirt or mold.
What are MultiGrow Rockwool Cubes used for?
They're ideal for transplanting rooted plugs or small cubes in hydroponic and soilless systems. While you can start seeds or cuttings directly in them, most growers begin in smaller plugs and step up into the 75mm cube.
Do MultiGrow Rockwool Cubes contain nutrients or affect pH?
No—these cubes are inert and chemically neutral. They don’t contain nutrients, so your feeding solution supplies everything. If not pre-soaked, rockwool may cause initial pH drift.
Do I need to soak MultiGrow Rockwool Cubes before use?
Yes—soak them in pH-adjusted water (typically pH 5.5–5.8) until fully saturated. Don’t squeeze the cubes—just let them drain naturally to maintain their air-to-water balance.
How should I water MultiGrow Rockwool Cubes?
Water only when the cube feels lighter. Rockwool holds moisture well but overwatering can suffocate roots. Always let excess water drain—don't let cubes sit in runoff or stay soaked.
How do I transplant into MultiGrow Rockwool Cubes?
Insert your starter plug snugly into the cube’s hole. Ensure good root contact without burying the stem too deep. You can gently backfill around the plug with rinsed rockwool if needed.
Which systems are compatible with MultiGrow Rockwool Cubes?
These cubes work in NFT, DWC (inside net pots), flood & drain, and drip systems. They're also often used with clay balls for stability or placed directly on rockwool slabs.
Can MultiGrow Rockwool Cubes grow algae or attract gnats?
Yes if the surface stays wet and exposed to light. Use covers, maintain airflow, and avoid overwatering to prevent algae or fungus gnats. A humidity dome can help early on—just don’t seal it forever.
What if a MultiGrow Rockwool Cube dries out?
If a cube goes bone dry, re-soak it slowly until fully saturated. Dry rockwool is harder to re-wet evenly and can stress young roots, so try to keep it moist but not wet.
What EC should I feed plants in MultiGrow Rockwool Cubes?
Use a low EC for new transplants, then increase as roots expand. A little runoff helps prevent salt buildup. If you notice salt crusting or pH drift, flush the cube with mild, pH-balanced water.
Can I transplant MultiGrow Rockwool Cubes into soil, coco, or slabs?
Yes—just plant the whole cube into your chosen medium. Adjust watering to avoid over-saturating both the cube and surrounding media. You can also stack onto slabs for seamless hydro growth.
Are MultiGrow Rockwool Cubes reusable?
They're generally treated as single-use for hygiene and consistency. If you reuse them, remove roots, sterilise thoroughly, and recondition with pH-adjusted water before planting again.
How do I dispose of used MultiGrow Rockwool Cubes?
Let them dry, remove any organic material, and dispose of according to local waste rules. While not compostable, the ECOSE® binder is more eco-friendly than traditional options.
Are MultiGrow Rockwool Cubes safe to handle?
Rockwool can irritate some people’s skin or lungs when dry or cut. Wear gloves, and a mask if handling many cubes or trimming. Avoid squeezing to preserve the cube’s structure.
Why do MultiGrow Rockwool Cubes support strong root growth?
The vertical fibre structure helps distribute moisture and oxygen evenly, encouraging rapid root expansion. That consistency makes them ideal for propagation and greenhouse environments.
