> So far have sorted out this method of washing pumice. Is there a better > way to wash a bigger quantity at a time? Not commercial quantities > but a sack full at a time. > > I used shade cloth in a wire frame work. Will have to peg the cloth > down next time. I wash clay non-clumping cat litter, "Sophisticat Pink" here, UK, by filling a leaky bucket and pouring water through it. The fines end up at the bottom. I wash it to release the initial wetting scent which may or may not effect plants. On a larger scale just fill a small water butt or plastic waste bin, with water and pour the pumice in until near the surface of the water, and then let the water out at the bottom, or scoop out the pumice from the top and leave the dirty water behind. I have used a similar technique to recover a particularly wanted grit from used compost. Just swill it around and pour off the organic and fines. The grit stays in the bottom. Brian Whyer, UK