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Recycled Glass Bottles Could Replace Perlite & Pumice

by Nate Downey

A Santa Fe-based company is days away from opening up a very cool factory. Located at the Albuquerque city dump and recycling center, Growstone, LLC, is turning used glass bottles into a substitute for perlite, used in hydroponic growing applications and as a hygroscopic (water retaining) soil amendment. My guess is that their product will also soon be seen as an excellent alternative to pumice—at least when replacing the essential ingredient in one of may favorite passive water harvesting techniques, the pumice wick.

There’s a chapter in Harvest the Rain about pumice wicks, so you may have to buy the book (which will be out in two weeks) to learn how to install one. For now, just imagine an extra-wide, super-thick, and ultra-long, underground sponge. You plant on either side of this sponge (or wick) and the roots of your plants suckle up to the sucker like piggies on teats.

Due to the high cost of shipping, up until recently pumice wicks were only feasible for folks who live relatively close to pumice mines. But this may be changing thanks to Growstones’s ability to ship “anywhere” in 35 cu. ft. recycled plastic bags. I met with Pat Beare, Growstones’s factory manager the other day, and he had to admit that the main focus of the company’s marketing plan has been on getting into the perlite market, but we both agreed that there is extremely awesome potential when it comes to the possible replacement of pumice for growstone (which is a registered trademark, btw).

Both perlite and pumice are mined from the Earth and typically cause terribly negative environmental damage. I would always justify this damage because we were putting pumice to such great use as a water harvesting technique that requires no pumping (as in active water harvesting systems) and loses no water to evaporation (in passive water harvesting applications). Now that there seems to be a product that will allow us to not degrade our forests and streams while we  simultaneously use a locally recycled material, my affection for the pumice wick, er, I mean glass-bottle wick, is growing fast like the belly of a happy young hog at dinnertime.

07/11/2010 | Books | Ecology | Water Harvesting | (0) Comments