A ponder only needs ro be concerned with western bentonite if your
interested in sealing a dirt type pond.........which on average
swells up to 20- 22 times its dry size. It is sodium based IIRC. There
is also huge deposits of Bentonite in the southeast, with Alabama
having one of the largest bentonite mines, but it is calcium
based......and will only swell up to 5 x its dry size........I use
both western and southern bentonite for my greensand (foundry sand for
casting metals) as one bentonite is not suitable as it lacks what the
other has, so blends are necessary. The mine here is only about 10
miles from my place, and I have free access to any bentonite that gets
spilled on the floor of the warehouse.......they bring in western
bentonite and stock it here, and I also get it as its always busting
bags and large 10,000 pound containers its shipped in......Bentonite
(western) will seal a pond very effectively if its mixed in the soil
prior to filling the pond with water, or if a pond leaks it can be
braodcast on the surface, and seepage or flowing leaks will pull it
into the voids where it accumulates and swells thus effectively
plugging up a leak or sealing a seeping pond. Its dirt cheap. The so
called Koi clay is actually southern bentonite........both western and
southern are montmoriliate (sp?) clays, and are collodial in nature. I
would look for a place in the UK that sells foundry products and ask
for it there. I know foundry work is big stuff in the UK, so its bound
to be there as its the most commonly used material for making
greensand.......They should have sodium asa well as calcium bentonites
as it takes both kinds to make foundry sands.

I may have the calcium mixed up with the sodium, but western what ever
it is is whats used for sealing ponds........and koi clay is southern





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Put some color in your cheeks...garden naked!