diff --git a/database/Amm.dat b/database/Amm.dat
index 604e8e32..d38840e9 100644
--- a/database/Amm.dat
+++ b/database/Amm.dat
@@ -316,11 +316,11 @@ AmmH+ = Amm + H+
 	-dw 2.28e-9
 AmmH+ + SO4-2 = AmmHSO4-
 #NH4+ + SO4-2 = NH4SO4-
-	-gamma 6.54 -0.08
-	-log_k 1.106;	-delta_h 4.3 kcal
-	-Vm -3.23 0 -68.42 0 -14.27 0 68.51 0 -0.4099 0.2339
-	-viscosity 0.24 0 0 3.3e-3 -0.1 0.528 0.748
-	-dw 1.35e-9 500 12.5 3 -1
+	-gamma 2.08 -0.0416
+	-log_k	1.211; -delta_h 8.56 kJ
+	-Vm -8.78 0 -36.09 0 -8.60 0 87.62 0 -0.3123 0.1172
+	-viscosity 0 0.116 -8.6e-3 0.159 -9.3e-3 0.522 0.627
+	-dw 0.9e-9 100 2.1 2 0
 H3BO3 = H2BO3- + H+
 	-log_k -9.24
 	-delta_h 3.224 kcal
diff --git a/database/phreeqc.dat b/database/phreeqc.dat
index 00ca4920..01cdbe3c 100644
--- a/database/phreeqc.dat
+++ b/database/phreeqc.dat
@@ -320,11 +320,11 @@ NH4+ = NH3 + H+
 	-dw 2.28e-9
 #AmmH+ + SO4-2 = AmmHSO4-
 NH4+ + SO4-2 = NH4SO4-
-	-gamma 6.54 -0.08
-	-log_k 1.106;	-delta_h 4.3 kcal
-	-Vm -3.23 0 -68.42 0 -14.27 0 68.51 0 -0.4099 0.2339
-	-viscosity 0.24 0 0 3.3e-3 -0.1 0.528 0.748
-	-dw 1.35e-9 500 12.5 3 -1
+	-gamma 2.08 -0.0416
+	-log_k	1.211; -delta_h 8.56 kJ
+	-Vm -8.78 0 -36.09 0 -8.60 0 87.62 0 -0.3123 0.1172
+	-viscosity 0 0.116 -8.6e-3 0.159 -9.3e-3 0.522 0.627
+	-dw 0.9e-9 100 2.1 2 0
 H3BO3 = H2BO3- + H+
 	-log_k -9.24
 	-delta_h 3.224 kcal
diff --git a/database/phreeqc_rates.dat b/database/phreeqc_rates.dat
index 9ee0f4d6..2c777a45 100644
--- a/database/phreeqc_rates.dat
+++ b/database/phreeqc_rates.dat
@@ -316,11 +316,11 @@ NH4+ = NH3 + H+
 	-dw 2.28e-9
 #AmmH+ + SO4-2 = AmmHSO4-
 NH4+ + SO4-2 = NH4SO4-
-	-gamma 6.54 -0.08
-	-log_k 1.106;	-delta_h 4.3 kcal
-	-Vm -3.23 0 -68.42 0 -14.27 0 68.51 0 -0.4099 0.2339
-	-viscosity 0.24 0 0 3.3e-3 -0.1 0.528 0.748
-	-dw 1.35e-9 500 12.5 3 -1
+	-gamma 2.08 -0.0416
+	-log_k	1.211; -delta_h 8.56 kJ
+	-Vm -8.78 0 -36.09 0 -8.60 0 87.62 0 -0.3123 0.1172
+	-viscosity 0 0.116 -8.6e-3 0.159 -9.3e-3 0.522 0.627
+	-dw 0.9e-9 100 2.1 2 0
 H3BO3 = H2BO3- + H+
 	-log_k -9.24
 	-delta_h 3.224 kcal