Two broiler poor pen experiments lasting 50 and 48 days, respectively, were conducted to compare the performance of a new, granular, acidified clay poultry litter amendment (Poultry Guard (TM)) and two other commercially available products. In Experiment 1, ammonia levels and litter pH were compared for the acidified clay, sodium bisulfate, and alum versus an untreated control. All three litter treatments reduced ammonia levels for up to 30 days relative to the untreated control. Broiler performance benefits and reduced beetle counts were obtained for all three litter amendments. In Experiment 2, the effect of increasing acid loading of the acidified clay (from 36% to 46% acid) were compared to alum and untreated control. As before, the litter amendments provided benefits (ammonia, litter pH reduction, and broiler performance gains) when compared to the untreated control. The 46% acid-loaded clay gave a statistically significant improvement in adjusted feed conversion and breast blister scores, but was matched by the 36% acid-loaded clay and alum treatments in most other areas.