Betsyann, Welcome to BYC.
Can you tell us what kind of soil is under your shavings? Do you have good drainage/percolation? If not first take care of that as wet dirt will cause all kinds of trouble for your birds if it stays wet after it rains. Second, sand is a good system for a lot of folks and it is the base of my run as I live in Florida. I use hay and straw mix on top of the sand and about once or twice per year I turn it under and add new hay/straw mix. In between turnings I just add more hay/straw and sprinkle with "food grade" Diatomacious earth. I have not had a ripe run since I started this.
Next thing to check is what your feed consists of. Are your chickens leaving runny wet stools? If so you may want to rethink your feed. Look on here for fermented feed and see if that is something you may be interested in.
Jim