I am building my new Koi pond and plan on using Sodium Bentonite Clay (either Benseal or Cetco Super GelX) to seal the bottom instead of a liner. Sides and some of the bottom are stone and concrete. The dirt bottom is about 12' x 8' (96 sq ft). Water will be about 3' deep.
Steps:
Till, rake and compact soil
Lay down 250 lbs of clay (5 bags), compact
This is a blanket seal method so I won't be mixing it into the soil
Cover with 1-2" of sand to confine the clay
Does anyone have experience with this method?
I used this video as a reference...
https://www.youtube.com/watch?v=IkUGu8h73dk&t=116s