Rockwool is a popular and economical hydroponic substrate because it is cheap, lightweight, highly absorbent, and extremely efficient. ROCKAL provides high-quality selection of stone/rock/mineral wool products which provide uniform distribution of water and plant nutrients.
Using rockwool as a hydroponic substrate gives you fantastic advantages over traditional growing media for your indoor garden.
Firstly, the water holding capacity is much greater, meaning litre for litre it can hold substantially more water than coco coir or soil. It also releases this water much easier than soil or coco does, meaning the plant does not use as much energy obtaining the water from the substrate. This means you can use a lot smaller volume of media, and your plant has more energy available for vegetative or generative growth above ground.
As rockwool is inert and contains no nutrients you have complete control over what your plants are fed. This also means that you need to be a little more careful with your pH and EC levels as whatever you give your plants is what they will get! There is no buffer or ‘forgiveness’ you would get from soil or coco.