I've tried almost every brand of litter that there is and I keep going back to Dr. Elsey's Precious Cat Scoopable Unscented Litter. It forms hard clumps and isn't very dusty either. My cat Sky was diagnosed with mild asthma and this litter seems to agree with him much more than any other that I've used. You can buy it at Petsmart or online. I get mine at Pet Club and maybe a few other pet stores may carry it by now. Good luck.