Aim of present study was to use the wood chips (sawdust) as a cheap substrate and source of carbon in the ammonia fixation and its impact on increasing the survival chance of fishes. According to this, fished were divvied into control group (Aquarium without sawdust) and treatment group (Aquarium containing to %10 of total volume) with four replications. 10 mg of ammonia was added to the aquarium and were calculated ammonia levels 24, 48, 72 96 hours after the addition of ammonia. In second stage, in addition to wood chips, aquarium containing the fishes. The mortality was counted in intervals of 24, 48, 72 and 96 hours after the addition of ammonia. Results were significant difference (p<0/05) between concentrations of ammonia in the treatment group compared with the control group. The lowest mortality rate was related to the ammonia treatment groups. Result of present study showed that the use of wood chips can increase the efficiency of ammonia fixation biological systems and increase survival chance of the fish.