seeing at this is the pellet posting... check this out:
http://cgi.ebay.com/25-POUNDS-OF-PLASTI ... .m20.l1116
If you search for PVC pellet on Ebay there is a company called Empire Wire and Supply that sells them... it's $75 for a 25# box...and $18 for a 5# box... my hubby and I bought a 25# box last MARCH and we STILL have a TON of them left. We have 3 cats and we foster homeless kitties...(not to mention they track those little suckers all over the house..) so... I would say the a $75 investment is WELL worth it, considering they ding you about $22-25 for each little box of those other pellets.
We also found that fewer of them get "Eaten" by the box.. (you know how they get all pushed up behind the bowl and the you lose half of them to the CatGenie monster...)... These pellets seem to only be slightly larger than the others.
Another thing is that they are softer, more rubbery..and seem to be more comfy for the kitties (I guess?)...
AND another thing... We have fewer clogs (I think I have had to deal with maybe 3 or 4 clogs due to pellets) in the last several months.
They don't float around, so I know they are getting cleaned.. they don't trap any odors (that we have noticed).
They don't mess with our plumbing at all (my husband IS a plumber.. and if he thought that it would screw anything up, he would be diametrically opposed to it..).
Check it out..you will be glad you did.

