Rockwool

Rockwool is a growing medium composed of a hydroponic lightweight substrate fashioned from spinning basaltic rock that is molten into fibers which are very fine, forming into various growing slabs, cubes, blocks, and granular products.

There are many advantages to growing with Rockwool, particularly hydroponically doing so. Rockwool presents a lengthy index of offerings to growers. Not only does it discourage pathogens from reproducing, but it also will help seeds to germinate and fosters draining adequately. 

Rockwool cubes are inorganic and sanitary when they have been exposed to intense temperatures. Rockwool will be a benefit if you are requiring a clean growing medium, this is due to the fact that it does not hold any organic matter within its composition. Therefore you are able to establish a protective zone in defense of harmful microbes. Though they are synthetic, they are compostable and will take a longer period of time to break down, but they will eventually. Shred the used blocks as finely as you can and compost them into your soil to add an additional kick.

Rockwool blocks will be saturated with liquid when you douse them with water, it will sap away as soon as each cube holds many tiny spaces in between the fibers which will be effective in draining the water out. Be careful with over watering as it can kill many plants in a grow operation by creating a safe and damp space for fungal pathogens or from suffocating roots and hampering growth. Choose adequate aeration to halt this in its tracks.

The cubes of Rockwool are great for germinating seeds by providing moisture (if kept in a state of saturation), warmth, and darkness. The seeds will be capable of establishing themselves quickly as the roots will be able to penetrate the fibers easily as compared to hard soils.