The growing use of carbon nanotubes is coming as a result of improvements in the production of nanotube materials – prices have come down significantly as volumes increase, vital for applications like water filtration, which have to be very affordable. - See more at: http://www.newelectronics.co.uk/electronics-technology/carbon-nanotubes-find-real-world-applications/58278/#sthash.6DXSUwPv.dpuf