Hi we have a small (<200 sqm) decorative pond about 1.2m deep that needs sealing. Has anyone used bentonite here in CM for this purpose and if so where did you get it? I suppose we could use a plastic liner but the kidney shape of the pond might make it a bit difficult to do. TIA

I take it this is just a natural pond,dug into the earth,and not

a concrete one ?,if that is the case,how is it leaking?,never

heard of Bentonite been used to seal ponds,it is just a clay?,

If the pond is a concrete one you could drain it ,let it dry and

apply a coat of special paint,I bought from Jotun,cannot remember

the name,as it was about 20 years ago when I sealed my pond

with it,and its still holding up,its a two part paint ,especially made

for sealing ponds,or anything containing water,so its safe for fish

etc, if you go to Jotun dealer I am sure they will be able to advise.

regards Worgeordie

Yes just dug out of rice paddy land. It is normally fed by the local irrigation canal but when they shut it off the water level slowly drops to zero in about 2 weeks.

If it's been dug in clay soil, it should seal itself.

If it's been dug in clay soil, it should seal itself.

It's definitely clay, like adobe. Mush when saturated, sticky when damp, hard as a rock when dry. It's been 2 years and several filling and soaking away cycles. How long would you give it?

If it's been dug in clay soil, it should seal itself.

It's definitely clay, like adobe. Mush when saturated, hard as a rock when dry. It's been 2 years and several filling and soaking away cycles. How long would you give it?

Can't help you with the time needed. Thought perhaps it was a new pond. Ours already existed on our land when we took over. Seemed to drain slowly, but now it only seems to evaporate.

You should puddle the clay

http://www.flowerpotman.com/gardenponds/howtomakeaclaypond.html

With the low rainfall this year and not so much the year before,the water

table must be a lot lower,plus you can get quite a bit of evaporation,

and the clay will be cracking with the Sun,you cannot just line it with

black plastic sheet,its too thin ,roots would grow through it,you need

special pond liner, Butyl is the best,but i have never seen any pond

liners for sale here.......concrete?

regards worgeordie