I generally use only coarse perlite - occasionally medium. Pieces are mostly under 1/4", and only a small volume would pass through insect screen. I think what you're up against with the very fine product you seem to have is that you will need to use much more to achieve the degree of drainage you'll find best than you would need if using the coarse. The physical aspect of the increased presence of perlite in itself isn't much of a specter, but the fluoride associated with larger %s of perlite in the mix might present a problem, especially in any plants that show a particular sensitivity to Fl.

Al

Yeah, thanks - I think I will try screening what I have, and look for another place to buy. I think Home Depot has medium or course...The stuff I got was not marked.

When I cat home I'll dump it all out into a container and see. maybe I just opened up the bottom of the bag and got the fines settled in one end. who knows. Thanks :)

I saw nothing near 1/4 inch yet. I'll check the rest though.

I sifted the perlite today through a metal screen door screen. I ended up with about 6 gallons of powder, and 15 gallons or so of good stuff. Is there anything useful to do with the powder?

Too late now, but don't breathe in the dust - wear a mask as you screen.

If you have clay soil in your garden(s)/ beds, incorporate it there. Perhaps someone else can think ......... oh yeah! - it would be great as part of the sand component in hypertufa, if you or friends are into troughs & stuff. If not - let me recommend it to you - it's great fun.

Al

A mask was worn!

Good idea with the raised beds. Our soil here is clay. I could probably do 1/2 compost (got some cooking for next year) 1/2 soil, and add the perlite powder. I'll hold onto it for later. thanks!