alternative materials to gravel for spring box back filling.

Hi. I recently posted about my spring project. Im getting to the point if collecting materials.

All articles i have seen have suggested back filling with gravel.

For my situation, getting gravel on site will be extremely difficult. I have access to expanded clay balls. Much lighter and easier to carry.

Would these work?

Would they break down too much?

Develop to much bacteria?

Or are there any other lighter alternatives to gravel?

I saw your post about getting some land in Portugal, how is it going?

I'm interested in visiting the country in the near future to find a project to work on, but am a bit concerned about drought and such things in the area, have you had any issues?

Hi T;
I would avoid using the clay for a backfill.
As it settles it will become a solid mass. Any attempt to dig things up later will be that much harder.
Its almost as heavy as the gravel would be. But sand makes a fine backfill when working with water lines and it is super easy to dig out later if need be.
A thin layer of your clay could top it off.

Is there road work anywhere around you? How about utility work? I don't know how it works in your locality, but in the U.S. "official" work usually makes a gesture toward good practice which, in this case, might mean using gravel or clean sand. If you find somebody using it, then your  mission (!) is to get what you need from them in some more or less civilized manner. How much do you need? It can go easy,  free and generous or it might not work for love or money - but always worth a friendly try.

Regards,
Rufus

well i am unsure of your project, but could broken up bits of concrete work for you?

with some luck and looking around you may be able to find a pile of broken concrete, also known as "urbanite" sometimes, to bulk up whatever gravel you can get?

Can you be clearer about what the 'spring project ' is ?