diff --git a/src/hydro/AnarchyDU/hydro_io.h b/src/hydro/AnarchyDU/hydro_io.h
index d78d16c35bf4ebb561116e1a504d24b248104206..4044a0c1f1cdbf4263de03071b046cd4c0884d2e 100644
--- a/src/hydro/AnarchyDU/hydro_io.h
+++ b/src/hydro/AnarchyDU/hydro_io.h
@@ -182,7 +182,7 @@ INLINE static void hydro_write_particles(const struct part* parts,
 
   list[4] = io_make_output_field(
       "InternalEnergies", FLOAT, 1, UNIT_CONV_ENERGY_PER_UNIT_MASS,
-      3. * hydro_gamma_minus_one, parts, u,
+      -3.f * hydro_gamma_minus_one, parts, u,
       "Co-moving thermal energies per unit mass of the particles");
 
   list[5] =
@@ -198,7 +198,7 @@ INLINE static void hydro_write_particles(const struct part* parts,
       xparts, convert_S, "Co-moving entropies per unit mass of the particles");
 
   list[8] = io_make_output_field_convert_part(
-      "Pressures", FLOAT, 1, UNIT_CONV_PRESSURE, 3.f * hydro_gamma, parts,
+      "Pressures", FLOAT, 1, UNIT_CONV_PRESSURE, -3.f * hydro_gamma, parts,
       xparts, convert_P, "Co-moving pressures of the particles");
 
   list[9] = io_make_output_field_convert_part(
diff --git a/src/hydro/AnarchyPU/hydro_io.h b/src/hydro/AnarchyPU/hydro_io.h
index 499ef5dc2d79f86f6f76c119b1b421260cf25cea..7dfe61f198163c458ea8ecc22c1cbaa7eb4b99dd 100644
--- a/src/hydro/AnarchyPU/hydro_io.h
+++ b/src/hydro/AnarchyPU/hydro_io.h
@@ -184,7 +184,7 @@ INLINE static void hydro_write_particles(const struct part* parts,
 
   list[4] = io_make_output_field(
       "InternalEnergies", FLOAT, 1, UNIT_CONV_ENERGY_PER_UNIT_MASS,
-      3. * hydro_gamma_minus_one, parts, u,
+      -3.f * hydro_gamma_minus_one, parts, u,
       "Co-moving thermal energies per unit mass of the particles");
 
   list[5] =
@@ -196,7 +196,7 @@ INLINE static void hydro_write_particles(const struct part* parts,
                                  "Co-moving mass densities of the particles");
 
   list[7] = io_make_output_field(
-      "Pressure", FLOAT, 1, UNIT_CONV_PRESSURE, 3.f * hydro_gamma, parts,
+      "Pressures", FLOAT, 1, UNIT_CONV_PRESSURE, -3.f * hydro_gamma, parts,
       pressure_bar, "Co-moving smoothed pressures of the particles");
 
   list[8] = io_make_output_field_convert_part(
diff --git a/src/hydro/Default/hydro_io.h b/src/hydro/Default/hydro_io.h
index 5d923837765c3d4759db37cd67badb40d75763f3..1944f677ff16c5f002aa4ee2f830c84e808ffa63 100644
--- a/src/hydro/Default/hydro_io.h
+++ b/src/hydro/Default/hydro_io.h
@@ -183,7 +183,7 @@ INLINE static void hydro_write_particles(const struct part* parts,
 
   list[4] = io_make_output_field(
       "InternalEnergies", FLOAT, 1, UNIT_CONV_ENERGY_PER_UNIT_MASS,
-      3. * hydro_gamma_minus_one, parts, u,
+      -3.f * hydro_gamma_minus_one, parts, u,
       "Co-moving thermal energies per unit mass of the particles");
 
   list[5] =
@@ -195,7 +195,7 @@ INLINE static void hydro_write_particles(const struct part* parts,
                                  "Co-moving mass densities of the particles");
 
   list[7] = io_make_output_field_convert_part(
-      "Pressures", FLOAT, 1, UNIT_CONV_PRESSURE, 3.f * hydro_gamma, parts,
+      "Pressures", FLOAT, 1, UNIT_CONV_PRESSURE, -3.f * hydro_gamma, parts,
       xparts, convert_P, "Co-moving pressures of the particles");
 
   list[8] = io_make_output_field_convert_part(
diff --git a/src/hydro/Gadget2/hydro_io.h b/src/hydro/Gadget2/hydro_io.h
index 9715558be39c853ec5a96262d95cdf4fe92309fa..20ad8e2d0c15094101e44999ff643f9d21619622 100644
--- a/src/hydro/Gadget2/hydro_io.h
+++ b/src/hydro/Gadget2/hydro_io.h
@@ -177,11 +177,11 @@ INLINE static void hydro_write_particles(const struct part* parts,
 
   list[7] = io_make_output_field_convert_part(
       "InternalEnergies", FLOAT, 1, UNIT_CONV_ENERGY_PER_UNIT_MASS,
-      3. * hydro_gamma_minus_one, parts, xparts, convert_part_u,
+      -3.f * hydro_gamma_minus_one, parts, xparts, convert_part_u,
       "Co-moving thermal energies per unit mass of the particles");
 
   list[8] = io_make_output_field_convert_part(
-      "Pressures", FLOAT, 1, UNIT_CONV_PRESSURE, 3.f * hydro_gamma, parts,
+      "Pressures", FLOAT, 1, UNIT_CONV_PRESSURE, -3.f * hydro_gamma, parts,
       xparts, convert_part_P, "Co-moving pressures of the particles");
 
   list[9] = io_make_output_field_convert_part(
diff --git a/src/hydro/GizmoMFM/hydro_io.h b/src/hydro/GizmoMFM/hydro_io.h
index b1d51cff90de52285abcd63c519aac911dcba7c2..711eee9e3117c220e6ab5a27a6d8f3557ec7ce13 100644
--- a/src/hydro/GizmoMFM/hydro_io.h
+++ b/src/hydro/GizmoMFM/hydro_io.h
@@ -220,15 +220,15 @@ INLINE static void hydro_write_particles(const struct part* parts,
                                  "Co-moving mass densities of the particles");
 
   list[7] = io_make_output_field_convert_part(
-      "Entropy", FLOAT, 1, UNIT_CONV_ENTROPY, 0.f, parts, xparts, convert_A,
+      "Entropies", FLOAT, 1, UNIT_CONV_ENTROPY, 0.f, parts, xparts, convert_A,
       "Co-moving entropies of the particles");
 
-  list[8] = io_make_output_field("Pressure", FLOAT, 1, UNIT_CONV_PRESSURE,
-                                 3.f * hydro_gamma, parts, P,
+  list[8] = io_make_output_field("Pressures", FLOAT, 1, UNIT_CONV_PRESSURE,
+                                 -3.f * hydro_gamma, parts, P,
                                  "Co-moving pressures of the particles");
 
   list[9] = io_make_output_field_convert_part(
-      "TotalEnergies", FLOAT, 1, UNIT_CONV_ENERGY, 3.f * hydro_gamma_minus_one,
+      "TotalEnergies", FLOAT, 1, UNIT_CONV_ENERGY, -3.f * hydro_gamma_minus_one,
       parts, xparts, convert_Etot, "Total (co-moving) energy of the particles");
 
   list[10] = io_make_output_field_convert_part(
diff --git a/src/hydro/GizmoMFV/hydro_io.h b/src/hydro/GizmoMFV/hydro_io.h
index 7288df0c510ea48489353b5be4ef9d3f252d5f59..11b8e95867495ccbc9df6a67b3045a09052fb161 100644
--- a/src/hydro/GizmoMFV/hydro_io.h
+++ b/src/hydro/GizmoMFV/hydro_io.h
@@ -219,15 +219,15 @@ INLINE static void hydro_write_particles(const struct part* parts,
                                  "Co-moving mass densities of the particles");
 
   list[7] = io_make_output_field_convert_part(
-      "Entropy", FLOAT, 1, UNIT_CONV_ENTROPY, 0.f, parts, xparts, convert_A,
+      "Entropies", FLOAT, 1, UNIT_CONV_ENTROPY, 0.f, parts, xparts, convert_A,
       "Co-moving entropies of the particles");
 
-  list[8] = io_make_output_field("Pressure", FLOAT, 1, UNIT_CONV_PRESSURE,
-                                 3.f * hydro_gamma, parts, primitives.P,
+  list[8] = io_make_output_field("Pressures", FLOAT, 1, UNIT_CONV_PRESSURE,
+                                 -3.f * hydro_gamma, parts, primitives.P,
                                  "Co-moving pressures of the particles");
 
   list[9] = io_make_output_field_convert_part(
-      "TotalEnergies", FLOAT, 1, UNIT_CONV_ENERGY, 3.f * hydro_gamma_minus_one,
+      "TotalEnergies", FLOAT, 1, UNIT_CONV_ENERGY, -3.f * hydro_gamma_minus_one,
       parts, xparts, convert_Etot, "Total (co-moving) energy of the particles");
 
   list[10] = io_make_output_field_convert_part(
diff --git a/src/hydro/Minimal/hydro_io.h b/src/hydro/Minimal/hydro_io.h
index a32e2c1a87c3219640ed94d56725632539121dd8..ba62489bcc8a7bff3b9d3cd45d9b9d0881772194 100644
--- a/src/hydro/Minimal/hydro_io.h
+++ b/src/hydro/Minimal/hydro_io.h
@@ -179,7 +179,7 @@ INLINE static void hydro_write_particles(const struct part* parts,
 
   list[4] = io_make_output_field(
       "InternalEnergies", FLOAT, 1, UNIT_CONV_ENERGY_PER_UNIT_MASS,
-      3. * hydro_gamma_minus_one, parts, u,
+      -3.f * hydro_gamma_minus_one, parts, u,
       "Co-moving thermal energies per unit mass of the particles");
 
   list[5] =
@@ -195,7 +195,7 @@ INLINE static void hydro_write_particles(const struct part* parts,
       xparts, convert_S, "Co-moving entropies per unit mass of the particles");
 
   list[8] = io_make_output_field_convert_part(
-      "Pressures", FLOAT, 1, UNIT_CONV_PRESSURE, 3.f * hydro_gamma, parts,
+      "Pressures", FLOAT, 1, UNIT_CONV_PRESSURE, -3.f * hydro_gamma, parts,
       xparts, convert_P, "Co-moving pressures of the particles");
 }
 
diff --git a/src/hydro/Planetary/hydro_io.h b/src/hydro/Planetary/hydro_io.h
index 6dd84b3e1b00beda160b4b51109b544ac0ad8b86..782e4de6dc05c8d5b485f9f4d2dadd685e44e3a7 100644
--- a/src/hydro/Planetary/hydro_io.h
+++ b/src/hydro/Planetary/hydro_io.h
@@ -176,7 +176,7 @@ INLINE static void hydro_write_particles(const struct part* parts,
       "Smoothing lengths (FWHM of the kernel) of the particles");
   list[4] = io_make_output_field(
       "InternalEnergies", FLOAT, 1, UNIT_CONV_ENERGY_PER_UNIT_MASS,
-      3. * hydro_gamma_minus_one, parts, u,
+      -3.f * hydro_gamma_minus_one, parts, u,
       "Thermal energies per unit mass of the particles");
   list[5] =
       io_make_output_field("ParticleIDs", ULONGLONG, 1, UNIT_CONV_NO_UNITS, 0.f,
@@ -190,7 +190,7 @@ INLINE static void hydro_write_particles(const struct part* parts,
       io_make_output_field("MaterialIDs", INT, 1, UNIT_CONV_NO_UNITS, 0.f,
                            parts, mat_id, "Material IDs of the particles");
   list[9] = io_make_output_field_convert_part(
-      "Pressures", FLOAT, 1, UNIT_CONV_PRESSURE, 3.f * hydro_gamma, parts,
+      "Pressures", FLOAT, 1, UNIT_CONV_PRESSURE, -3.f * hydro_gamma, parts,
       xparts, convert_P, "Pressures of the particles");
   list[10] = io_make_output_field_convert_part(
       "Potentials", FLOAT, 1, UNIT_CONV_POTENTIAL, 0.f, parts, xparts,
diff --git a/src/hydro/PressureEnergy/hydro_io.h b/src/hydro/PressureEnergy/hydro_io.h
index 0582d39955ad1cf6617b674a590e9b4fb6d2c0d3..896d0137ca7aae2d17159e4dbf335a9263dce3a7 100644
--- a/src/hydro/PressureEnergy/hydro_io.h
+++ b/src/hydro/PressureEnergy/hydro_io.h
@@ -175,7 +175,7 @@ INLINE static void hydro_write_particles(const struct part* parts,
 
   list[4] = io_make_output_field(
       "InternalEnergies", FLOAT, 1, UNIT_CONV_ENERGY_PER_UNIT_MASS,
-      3. * hydro_gamma_minus_one, parts, u,
+      -3.f * hydro_gamma_minus_one, parts, u,
       "Co-moving thermal energies per unit mass of the particles");
 
   list[5] =
@@ -187,7 +187,7 @@ INLINE static void hydro_write_particles(const struct part* parts,
                                  "Co-moving mass densities of the particles");
 
   list[7] = io_make_output_field(
-      "Pressures", FLOAT, 1, UNIT_CONV_PRESSURE, 3.f * hydro_gamma, parts,
+      "Pressures", FLOAT, 1, UNIT_CONV_PRESSURE, -3.f * hydro_gamma, parts,
       pressure_bar, "Co-moving smoothed pressures of the particles");
 
   list[8] = io_make_output_field_convert_part(
diff --git a/src/hydro/PressureEnergyMorrisMonaghanAV/hydro_io.h b/src/hydro/PressureEnergyMorrisMonaghanAV/hydro_io.h
index 3996197422f05fa58b36cd2f1617bd88617f1945..7da369847a5d684ebe30dbf7428ea3da9a8c216f 100644
--- a/src/hydro/PressureEnergyMorrisMonaghanAV/hydro_io.h
+++ b/src/hydro/PressureEnergyMorrisMonaghanAV/hydro_io.h
@@ -176,7 +176,7 @@ INLINE static void hydro_write_particles(const struct part* parts,
 
   list[4] = io_make_output_field(
       "InternalEnergies", FLOAT, 1, UNIT_CONV_ENERGY_PER_UNIT_MASS,
-      3. * hydro_gamma_minus_one, parts, u,
+      -3.f * hydro_gamma_minus_one, parts, u,
       "Co-moving thermal energies per unit mass of the particles");
 
   list[5] =
@@ -188,7 +188,7 @@ INLINE static void hydro_write_particles(const struct part* parts,
                                  "Co-moving mass densities of the particles");
 
   list[7] = io_make_output_field(
-      "Pressures", FLOAT, 1, UNIT_CONV_PRESSURE, 3.f * hydro_gamma, parts,
+      "Pressures", FLOAT, 1, UNIT_CONV_PRESSURE, -3.f * hydro_gamma, parts,
       pressure_bar, "Co-moving smoothed pressures of the particles");
 
   list[8] = io_make_output_field_convert_part(
diff --git a/src/hydro/PressureEntropy/hydro_io.h b/src/hydro/PressureEntropy/hydro_io.h
index d7591fbdea1576cf6fec645c7a9842f2197b60a3..8ac77f31efde3b708cbf631c792404b135e4c112 100644
--- a/src/hydro/PressureEntropy/hydro_io.h
+++ b/src/hydro/PressureEntropy/hydro_io.h
@@ -188,11 +188,11 @@ INLINE static void hydro_write_particles(const struct part* parts,
 
   list[7] = io_make_output_field_convert_part(
       "InternalEnergies", FLOAT, 1, UNIT_CONV_ENERGY_PER_UNIT_MASS,
-      3. * hydro_gamma_minus_one, parts, xparts, convert_u,
+      -3.f * hydro_gamma_minus_one, parts, xparts, convert_u,
       "Co-moving thermal energies per unit mass of the particles");
 
   list[8] = io_make_output_field_convert_part(
-      "Pressures", FLOAT, 1, UNIT_CONV_PRESSURE, 3.f * hydro_gamma, parts,
+      "Pressures", FLOAT, 1, UNIT_CONV_PRESSURE, -3.f * hydro_gamma, parts,
       xparts, convert_P, "Co-moving smoothed pressures of the particles");
 
   list[9] = io_make_output_field(
diff --git a/src/hydro/Shadowswift/hydro_io.h b/src/hydro/Shadowswift/hydro_io.h
index e6190e5a6740a758b4bc9b077dcaaf4661b6c261..31840a05ee436d5b535ae022bd79118851ef4e5b 100644
--- a/src/hydro/Shadowswift/hydro_io.h
+++ b/src/hydro/Shadowswift/hydro_io.h
@@ -156,7 +156,7 @@ INLINE static void hydro_write_particles(const struct part* parts,
 
   list[4] = io_make_output_field_convert_part(
       "InternalEnergies", FLOAT, 1, UNIT_CONV_ENERGY_PER_UNIT_MASS,
-      3. * hydro_gamma_minus_one, parts, xparts, convert_u,
+      -3.f * hydro_gamma_minus_one, parts, xparts, convert_u,
       "Co-moving thermal energies per unit mass of the particles");
 
   list[5] =
@@ -168,13 +168,13 @@ INLINE static void hydro_write_particles(const struct part* parts,
                                  "Accelerations of the particles(does not "
                                  "work in non-cosmological runs).");
 
-  list[7] = io_make_output_field("Densities", FLOAT, 1, UNIT_CONV_DENSITY,
-                                 3.f * hydro_gamma, parts, primitives.rho,
+  list[7] = io_make_output_field("Densities", FLOAT, 1, UNIT_CONV_DENSITY, -3.f,
+                                 parts, primitives.rho,
                                  "Co-moving mass densities of the particles");
 
-  list[8] = io_make_output_field("Volumes", FLOAT, 1, UNIT_CONV_VOLUME,
-                                 3.f * hydro_gamma, parts, cell.volume,
-                                 "Co-moving volumes of the particles");
+  list[8] =
+      io_make_output_field("Volumes", FLOAT, 1, UNIT_CONV_VOLUME, -3.f, parts,
+                           cell.volume, "Co-moving volumes of the particles");
 
   list[9] = io_make_output_field("GradDensities", FLOAT, 3, UNIT_CONV_DENSITY,
                                  1.f, parts, primitives.gradients.rho,
@@ -185,11 +185,11 @@ INLINE static void hydro_write_particles(const struct part* parts,
       "Co-moving entropies of the particles");
 
   list[11] = io_make_output_field("Pressures", FLOAT, 1, UNIT_CONV_PRESSURE,
-                                  3.f * hydro_gamma, parts, primitives.P,
+                                  -3.f * hydro_gamma, parts, primitives.P,
                                   "Co-moving pressures of the particles");
 
   list[12] = io_make_output_field_convert_part(
-      "TotalEnergies", FLOAT, 1, UNIT_CONV_ENERGY, 3.f * hydro_gamma_minus_one,
+      "TotalEnergies", FLOAT, 1, UNIT_CONV_ENERGY, -3.f * hydro_gamma_minus_one,
       parts, xparts, convert_Etot, "Total (co-moving) energy of the particles");
 }