Rockwool Vs. Sphagnum Peat Moss

Rockwool and sphagnum peat moss are alternative growing media for hydroponics. Molten rocks are spun into fibers to create rockwool. Sphagnum peat moss is a natural plant derived from peat bogs.

Description

The texture of rockwool resembles that of insulation material. It is manufactured as small cubes or large slabs. Sphagnum peat moss is manufactured as dry blocks. After soaking in water, long strands of moss spread out.

Function

Rockwool and sphagnum peat moss provide support, aeration and a supply of water for plants grown hydroponically. They fulfill the same role that soil has for normally grown plants.

Advantages

Both rockwool and sphagnum peat moss absorb and retain large amounts of water. Both provide great aeration for the plant root system. This ensures the plant root system has access to oxygen.

Disadvantages

Rockwool is not environmentally friendly because it does not decompose. The dust and fibers from rockwool pose a health risk. When handling rockwool, wear a dust mask for protection. Sphagnum peat moss decomposes over time and releases particles that can clog the pump or drip system of the hydroponic setup.

Considerations

For lattice or net-pot containers, sphagnum peat moss is recommended because of its strand structure and great water absorption. For plants with huge root systems, rockwool slabs are recommended.

References

• Simply Hydro: Using Rockwool
• Greenhouse Product News: Alternative Hydroponic Substrates