What Grodan Grow Chunks Do That Perlite Cannot
Most aeration amendments trade one thing for another. Perlite opens a mix up and holds almost nothing. Clay pebbles drain fast and hold less again. Stone wool is unusual because the fibre structure does both, creating air space while still holding water inside the chunk itself. Broken into loose pieces, that gives a medium which lifts the air content of a pot without drying the pot out in the process. It is the same substrate as the blocks and slabs, so a room already on stone wool adds no new variable to its irrigation.
Using Stone Wool Chunks in Pots and Around Blocks
There are three common jobs. On its own in a pot or a bucket, as a straight substrate. Packed around a block, where the chunks bridge between the block and the container so roots leaving the block have somewhere to go. Or blended into another medium, layered with coco fibre or mixed with clay pebbles, to lift aeration in a mix that has gone heavy. The bag is 2 cubic feet, which is enough to fill a run of pots or to top up a bench. Light to handle and easy to wet through, and it takes irrigation the same way the rest of the Grodan range does.
Key Features
- Air and water together: Stone wool fibre holds water inside the chunk while opening the mix up.
- Not a perlite swap: Perlite adds air and holds almost nothing. This does both at once.
- Straight in a pot: Works on its own as a substrate in containers and buckets.
- Packed around a block: Gives roots leaving a Gro-Block somewhere to go inside the pot.
- Blends with anything: Layer with coco fibre or mix with clay pebbles to lift a heavy medium.
- 2 cubic feet a bag: Enough to fill a run of pots or top up a propagation bench.
- Same substrate as the blocks: A stone wool room keeps one irrigation strategy across the bench.
- Light to handle: Loose chunks move and wet through without the weight of a bagged mix.
- Wets evenly: No dry core to work around once the bag has been run through once.
Technical Specifications
| Specification | Value |
|---|---|
| Brand | Grodan |
| Part Number | 70039-S |
| Product | Stone Wool Grow-Chunks |
| Volume | 2 cubic feet |
| Form | Loose chunks |
| Substrate | Stone wool |
| Use, Standalone | As substrate in pots and containers |
| Use, With Blocks | Packed around a Gro-Block inside a larger pot |
| Use, Blended | Layered with coco fibre or mixed with clay pebbles |
| Function | Adds aeration while retaining water |
| Suits | Hydroponic systems and container growing |