Cat litter lining

A while back, while reading about natural pools and ponds, I ran across numerous articles where people had used clumping cat litter to line the bottom of their ponds. Supposedly it is mixed with the existing soil along the bottom and bonds into a water resistant seal. The basic requirement was that you pick a litter that is pure sodium bentonite clay without additives, but several people noted that they found a source that was half the cost of buying bentonite from a pool company. I find myself wondering if anyone here has actually done this however. I imagine if done wrong, there are some serious horror stories to be had as well. Has anyone here had experiences, both good and bad, with this?

I tried this with a small decorative pond I have, but the few bags I bought did not make a thick enough layer to seal the pond.

I guess it comes down to economics of scale.  

They are going to charge you a fair bit of money to pelletize bentonite and put it in a bag for you to use it for cats,
but it'll probably work out cheaper to buy it in bulk form from a supplier for pond use.

My bet is that the "clumping cat litter' contained Bentonite clay. You are better off just buying bulk Bentonite clay for MUCH less. A raw material is always going to me significantly less expensive than a manufactured retail product.
Or use a pond liner.

I don't know about "clumping" cat litter, or what they add to make it clump, but plain unscented no additives cat litter is a great source for small amounts of bentonite, which absorbs so much water I was astonished.  A little goes a long way, but it would never substitute for a truck load of clay,or bags of bentonite.

The pond I have is dug into mostly clay, and I want the water to seep some to water the surrounding ground, so a pond liner is not for me.

Using cat litter diluted to the consistency of "snot" is usable for cob building, but that is the extent of my experience.

Thekla McDaniels wrote:I don't know about "clumping" cat litter, or what they add to make it clump,

It's the clay that makes it clump. Clumping means it is mostly clay.

Bentonite clay can be bought at any well drilling supply outlet. Cost aprox $13 for a 50lb bag.
There are several ways to add the bentonite. If your pond is empty then it can be added and then mixed with the existing material in the pond using a tiller.
If you have a pond with some existing water you can spread the powder on top the water and let it sink over time. This will have to be done using a sieve as adding directly from the bag will lead to clumping, which could float around for months. The other method is to pre mix as a slurry and pour this into the pond. The theory is that the clay will be drawn to the area of the leak and plug it up.