I did get some PP at Sears - 6 oz for $5. 6 oz is about the same price per
oz as ebay after shipping. There was a previous post that said they had
found like 5 lbs for $18 at Tractor Supply Co. It will keep for a very long
time but take forever to use that much, since you are talking only grams per
application, outside of a pond. Remember you are not treating for snails
per se but for bacteria or parasites that you dont want to transfer to your
pond. I dont believe there is any organic way to remove those critters
including 'aging'. If you want to save the frog eggs, I have treated in a 5
gallon pail. Sorry I cant find my notes at the moment but it only requires
a very small amount to treat a 5 gal pail. I believe the dose for plants is
1.5 grams - not much - for about an hour.
Bill Brister - Austin, Texas