(I hope I spelled that right.) What exactly is this made of? Is it biodegradeable? If so, how fast does it break down?

My understanding is that Stall-Dry as well as Sweet PDZ are made from some sort of clay, DE (diatomacious earth...uncertain of spelling) and a few other chemicals.

It really will help absorb the urine and ammonia However... it is not something that is good for the rabbits to come into direct contact with. Also , if in powder form... it can really irratate the bunny noses. Saying that... we have used Sweet PDZ in granular form during the summer... it certainly helped with oders... definately Not the pocketbook !

I was thinking about putting it on the ground under my cages (which are in racks). Would that be ok, do you think? The upper cages all have poo pans, but the lower cages do not.

I've used Sweet PDZ, and will tell you this much--it's NOT something you'd ever want to use in metal drip pans. The chemicals in it will cause corrosion to happen at an increased rate.

For what you're describing, I'd suggest getting either hydrated lime or barnyard lime and going with those. They will accomplish the same thing in terms of odor control and cost considerably less in the process.

Stall Dry is made of volcanic rock and it works amazingly well. You can put pure ammonia on your hand pat on a bit of stall dry and you will never have known you'd ever had ammonia on you. It is also beneficial to compost and helps speed up the process.

I Liked Stall-dry-- and yes, it does neutralize ammonia VERY well-- I had more issue with Sweet PDZ in the dropping pans-- it like, turned to concrete! And DE in the dropping pans is effective for odor control, and is wonderful on the ground-- Stall Dry is mostly DE---