Time and time again it has proven its superiority inmeeting the needs of commercial growers and home gardeners. Hydroponic culture isno exception. Extensive testing over a period of years has documented thesuperiority of perlite over other methods of hydroponic culture. Watering As a rooting medium, perlite is superiorto rockwool. The outstanding feature of perlite is the ease with whicha constant supply of water and nutrients can be maintained in the substratesimply by placing the plant container in a shallow reservoir of nutrientsolution.
Excess solution remains in the reservoir.
Roots in perlite are always well aerated andwell watered. Nutrient solution may have to be added torockwool slabs as often as 24 times per day. To avoid the possibility of waterloggingwhen rockwool is used, polyethylene sleeves of rockwool slabs should beslit to drain out excess nutrient solution. This continual waste of waterand fertilizers can increase the combined cost of these items to more thandouble that for perlite culture where a reservoir system can be easilyadapted. Some growers have used perlite for tomatoes more thanone growing season and it has subsequently been re-used for potting mixesand soil conditioning.