100% Natural & organic, OMRI Listed. Each brick weighs 1.4 lbs | High-grade coconut coir with low EC and pH levels | Provides plenty of aeration and drainage, Contains only coconut pith and fibers | Our coco coir products are organic, guaranteed to be very high quality and very low salt content. Very low level of EC is attained by repited washing with fresh water. | 100% natural, renewable replacement for peat moss, rockwool & perlite