Coco aka Coir has a similar look as soil but behaves in a different manner. It is a much finer and lighter media giving the grower a better air to water ratio. As coco is a lighter growing media it does not hold as much water or nutrients as soil, meaning it needs watering and monitoring more often. If the plants are over fed it is much easier to flush the plant nutrients out of the coco. Plants will also grow slightly faster and taller in coco over soil. The pH has to been spot on when using coco as it does not buffer the same as soil.
Clay Pebbles are the least forgiving out of the grow media's, however do not be put off by this. If the grower has the correct set up and products using clay pebbles, the grower can expect to get amazing results. It is important to note that clay pebbles have no way of retaining moisture, this will give the grower a very high air to water ratio meaning the plants will need watering many times per day. This can be achieved by using various hydroponic systems which are all available in store or online. Your pH levels will also have to be perfect as there is no way for the clay pebbles to buffer the levels.
A very good alternative to clap pebbles are Growstones. These are made from 100% recycled glass and are one of the most popular growing media in North America. Growstones are a highly porous grow media. It is designed to give an excellent air to water ratio without the risk of over watering.
Perlite is a non-toxic naturally occurring volcanic rock which is heated to high temperatures to produce a lightweight micro-porous material. Perlite has excellent water retention and drainage, this improves the aeration of the growing media.
Vermiculite is a naturally occurring, non toxic aluminium iron silicate mineral. It is then heated to extremely high temperatures which produces a lightweight mineral with a high surface area. Vermiculite is excellent at absorbing nutrients and preventing them from being washed away.