Styrofoam could be substituted, but how would you shred it small enough? (shudders while thinking of all those static-y bit of styrofoam clinging to everything)

Hi lil peaches
You can run the white bead board type styrofoam through your blender in chunks. It's pretty tough and breaks down into the little beads.
But a word of warning form my limited personal experince, these beads make very weak tufa.
Look around for a commercial builder supply house, Perlite can be veru inexpensive from them. As is vermiculite.
Both are actually cheaper than sand by volume.

Lilpeaches,
Seems like a long time ago that I tried shredded styrofoam. It is very difficult to get mixed in thoroughly, and has a tendency to float.
Dena

Lilpeaches,

I just purchased cryogenic perlite from a masonry supply house. A ganormous bag costs only $8.50

A much smaller bag of much larger pieces from the nursery was probably double the cost.

Cryogenic perlite is the really tiny pieces. It is not nearly as annoyingly stati-y as styrofoam. But it does have a tendency to float out of the bag.

Hope this helps.
Dora

Angela, I have put the styro that builders use ,in an old blender,and blended till it was small bits, and used it in a tufa mix( 1- part portland, 1- part sand and, 2 parts styro) the pot and shroom was so light it floated when I put it in the water bath, I had to place a heavy object on it to hold it down. The pot has been outside since last summer and it seems to be in good shape. The peanuts that items are packed in didn't work too good, it was very light in wieght and floated all over the place!
bonnie

Here is a link that might be useful: pic

Hi Rockyn
If you haven't used cryogenic perlite before you will love it.
You can also get fine Vermiculite sold a PoolPad in the same sized bag.
Poolpad vermiculite, Cryo Perlite, and fine Peat make a marvelou Tufa.

BlockFill is also a fine vermiculite and it might even be better because it is coated to shed water. I haven't tried it yet. No more room in the shed.:)
I'm well stocked for winter.

At Home Depot - there are small pricey bags of perlite - and then there are garbage can size bags of perlite that last forever and cost very little ...... not all the HD staff knows about BOTH - so you kind of have to look around - and especially look UP as it is often stashed on overhead shelves. Just one way to get around it - would not ever want to try to hand manage styrofoam breakdown - I can't even deal w/ packing peanuts without having wind and static have their way w/ me. LOL

HTH Vicki