The aim was to assess the efficacy of prophylactic health products (PHPs) on shrimp (Penaeus monodon) post larvae (PL) during the nursery phase. This included five treatments: infeed probiotic (F_PRO), water probiotic (W_PRO), a combination of water and infeed probiotic (FW_SYN), biofloc, a combination of biofloc and infeed probiotic (F_PRO&biofloc), and a no-treatment control, five replicates each. Each tank was filled with 450 L water and stocked with 700 PL15, weight 0.008 ± 0.00 g at a density of 1.56 PL/L, reared for 27 days. There were no significant differences in water temperature, dissolved oxygen, alkalinity, and total ammonia nitrogen among treatments and control. pH and nitrite were lower in biofloc and F_PRO&biofloc compared to other treatments. The final body weight, weight gain, specific growth rate and food conversion ratio were significantly higher (p ≤ .05) in F_PRO&biofloc compared to other treatments and control. A salinity stress test showed a significantly higher survival rate in F_PRO&biofloc followed by biofloc than other treatments and control. Our study indicated that rearing shrimp in biofloc alone or combined with infeed probiotic might increase growth and resistance to environmental stressors. Further on-farm trials are required to confirm the efficacy of the PHPs