diff --git a/csiborgtools/flow/flow_model.py b/csiborgtools/flow/flow_model.py
index e2e0865..1139e27 100644
--- a/csiborgtools/flow/flow_model.py
+++ b/csiborgtools/flow/flow_model.py
@@ -31,7 +31,9 @@ from jax import jit
 from jax import numpy as jnp
 from jax.scipy.special import erf, logsumexp
 from numpyro import factor, plate, sample
-from numpyro.distributions import MultivariateNormal, Normal, Uniform
+from numpyro.distributions import (Distribution, MultivariateNormal, Normal,
+                                   Uniform, constraints)
+from numpyro.distributions.util import promote_shapes
 from quadax import simpson
 from tqdm import trange
 
@@ -150,6 +152,35 @@ def upper_truncated_normal_logpdf(x, loc, scale, xmax):
     return normal_logpdf(x, loc, scale) - jnp.log(norm)
 
 
+###############################################################################
+#                          Inverse distribution                               #
+###############################################################################
+
+
+class InverseDistribution(Distribution):
+    """Inverse distribution."""
+    support = constraints.positive
+    args_contraints = {
+        "low": constraints.positive,
+        "high": constraints.positive,
+        "fiducial_scale": constraints.positive,
+    }
+    reparametrized_params = ["low", "high"]
+
+    def __init__(self, low, high, fiducial_scale=1.):
+        self.low, self.high = promote_shapes(low, high)
+        self.log_fiducial_scale = jnp.log(fiducial_scale)
+
+        super(InverseDistribution, self).__init__(batch_shape=())
+
+    def sample(self, key, sample_shape=()):
+        z = Uniform(0, 1).sample(key, sample_shape)
+        return self.high * (self.low / self.high)**z
+
+    def log_prob(self, value):
+        return - (jnp.log(value) - self.log_fiducial_scale)
+
+
 ###############################################################################
 #                          Base flow validation                               #
 ###############################################################################
@@ -314,11 +345,13 @@ def e2_distmod_SN(e2_mag, e2_x1, e2_c, alpha_cal, beta_cal, e_mu_intrinsic):
             + e_mu_intrinsic**2)
 
 
-def sample_SN(e_mu_min, e_mu_max, mag_cal_mean, mag_cal_std, alpha_cal_mean,
-              alpha_cal_std, beta_cal_mean, beta_cal_std, alpha_min, alpha_max,
+def sample_SN(mag_cal_mean, mag_cal_std, alpha_cal_mean, alpha_cal_std,
+              beta_cal_mean, beta_cal_std, alpha_min, alpha_max,
               sample_alpha, name):
     """Sample SNIe Tripp parameters."""
-    e_mu = sample(f"e_mu_{name}", Uniform(e_mu_min, e_mu_max))
+    # The low/high are used only to generate an initial guess, they only
+    # have to be in the right order of magnitude so that's why hardcoded.
+    e_mu = sample(f"e_mu_{name}", InverseDistribution(0.2, 0.5, 0.15))
     mag_cal = sample(f"mag_cal_{name}", Normal(mag_cal_mean, mag_cal_std))
     alpha_cal = sample(
         f"alpha_cal_{name}", Normal(alpha_cal_mean, alpha_cal_std))
@@ -350,15 +383,18 @@ def e2_distmod_TFR(e2_mag, e2_eta, eta, b, c, e_mu_intrinsic):
     return e2_mag + (b + 2 * c * eta)**2 * e2_eta + e_mu_intrinsic**2
 
 
-def sample_TFR(e_mu_min, e_mu_max, a_mean, a_std, b_mean, b_std,
-               c_mean, c_std, alpha_min, alpha_max, sample_alpha,
-               a_dipole_mean, a_dipole_std, sample_a_dipole, name):
+def sample_TFR(a_mean, a_std, b_mean, b_std, c_mean, c_std, alpha_min,
+               alpha_max, sample_alpha, a_dipole_mean, a_dipole_std,
+               sample_a_dipole, name):
     """Sample Tully-Fisher calibration parameters."""
-    e_mu = sample(f"e_mu_{name}", Uniform(e_mu_min, e_mu_max))
+    # The low/high are used only to generate an initial guess, they only
+    # have to be in the right order of magnitude so that's why hardcoded.
+    e_mu = sample(f"e_mu_{name}", InverseDistribution(0.2, 0.5, 0.15))
     a = sample(f"a_{name}", Normal(a_mean, a_std))
 
     if sample_a_dipole:
-        ax, ay, az = sample(f"a_dipole_{name}", Normal(a_dipole_mean, a_dipole_std).expand([3]))  # noqa
+        ax, ay, az = sample(f"a_dipole_{name}", Normal(
+            a_dipole_mean, a_dipole_std).expand([3]))
     else:
         ax, ay, az = 0.0, 0.0, 0.0
 
@@ -381,11 +417,13 @@ def sample_TFR(e_mu_min, e_mu_max, a_mean, a_std, b_mean, b_std,
 #                    Simple calibration parameters sampling                   #
 ###############################################################################
 
-def sample_simple(e_mu_min, e_mu_max, dmu_min, dmu_max, alpha_min, alpha_max,
-                  dmu_dipole_mean, dmu_dipole_std, sample_alpha,
-                  sample_dmu_dipole, name):
+def sample_simple(dmu_min, dmu_max, alpha_min, alpha_max, dmu_dipole_mean,
+                  dmu_dipole_std, sample_alpha, sample_dmu_dipole, name):
     """Sample simple calibration parameters."""
-    e_mu = sample(f"e_mu_{name}", Uniform(e_mu_min, e_mu_max))
+    # The low/high are used only to generate an initial guess, they only
+    # have to be in the right order of magnitude so that's why hardcoded.
+    e_mu = sample(f"e_mu_{name}", InverseDistribution(0.2, 0.5, 0.15))
+
     dmu = sample(f"dmu_{name}", Uniform(dmu_min, dmu_max))
     alpha = sample_alpha_bias(name, alpha_min, alpha_max, sample_alpha)
 
@@ -409,11 +447,13 @@ def sample_simple(e_mu_min, e_mu_max, dmu_min, dmu_max, alpha_min, alpha_max,
 
 
 def sample_calibration(Vext_min, Vext_max, Vmono_min, Vmono_max, beta_min,
-                       beta_max, sigma_v_min, sigma_v_max, h_min, h_max,
-                       rLG_min, rLG_max, no_Vext, sample_Vmono, sample_beta,
-                       sample_h, sample_rLG, sample_Vmag_vax):
+                       beta_max, h_min, h_max, rLG_min, rLG_max, no_Vext,
+                       sample_Vmono, sample_beta, sample_h, sample_rLG,
+                       sample_Vmag_vax):
     """Sample the flow calibration."""
-    sigma_v = sample("sigma_v", Uniform(sigma_v_min, sigma_v_max))
+    # The low/high are used only to generate an initial guess, they only
+    # have to be in the right order of magnitude so that's why hardcoded.
+    sigma_v = sample("sigma_v", InverseDistribution(100, 1000., 150.))
 
     if sample_beta:
         beta = sample("beta", Uniform(beta_min, beta_max))
diff --git a/scripts/flow/flow_validation.py b/scripts/flow/flow_validation.py
index c560a19..454d88c 100644
--- a/scripts/flow/flow_validation.py
+++ b/scripts/flow/flow_validation.py
@@ -190,6 +190,8 @@ def run_model(model, nsteps, nburn,  model_kwargs, out_folder,
         neg_ln_evidence = jax.numpy.nan
         neg_ln_evidence_err = (jax.numpy.nan, jax.numpy.nan)
 
+    # Temporarily disable saving.
+    return
     fname = join(out_folder, fname)
     print(f"Saving results to `{fname}`.")
     with File(fname, "w") as f:
@@ -236,16 +238,14 @@ def get_distmod_hyperparams(catalogue, sample_alpha, sample_mag_dipole):
     alpha_max = 10.0
 
     if catalogue in ["LOSS", "Foundation", "Pantheon+", "Pantheon+_groups", "Pantheon+_zSN"]:  # noqa
-        return {"e_mu_min": 0.001, "e_mu_max": 1.0,
-                "mag_cal_mean": -18.25, "mag_cal_std": 2.0,
+        return {"mag_cal_mean": -18.25, "mag_cal_std": 2.0,
                 "alpha_cal_mean": 0.148, "alpha_cal_std": 1.0,
                 "beta_cal_mean": 3.112, "beta_cal_std": 2.0,
                 "alpha_min": alpha_min, "alpha_max": alpha_max,
                 "sample_alpha": sample_alpha
                 }
     elif catalogue in ["SFI_gals", "2MTF"] or "CF4_TFR" in catalogue:
-        return {"e_mu_min": 0.001, "e_mu_max": 1.0,
-                "a_mean": -21., "a_std": 5.0,
+        return {"a_mean": -21., "a_std": 5.0,
                 "b_mean": -5.95, "b_std": 4.0,
                 "c_mean": 0., "c_std": 20.0,
                 "a_dipole_mean": 0., "a_dipole_std": 1.0,
@@ -254,8 +254,7 @@ def get_distmod_hyperparams(catalogue, sample_alpha, sample_mag_dipole):
                 "sample_alpha": sample_alpha,
                 }
     elif catalogue in ["CF4_GroupAll"]:
-        return {"e_mu_min": 0.001, "e_mu_max": 1.0,
-                "dmu_min": -3.0, "dmu_max": 3.0,
+        return {"dmu_min": -3.0, "dmu_max": 3.0,
                 "dmu_dipole_mean": 0., "dmu_dipole_std": 1.0,
                 "sample_dmu_dipole": sample_mag_dipole,
                 "alpha_min": alpha_min, "alpha_max": alpha_max,
@@ -299,16 +298,16 @@ if __name__ == "__main__":
     ###########################################################################
 
     # `None` means default behaviour
-    nsteps = 10_000
+    nsteps = 2_000
     nburn = 2_000
     zcmb_min = None
     zcmb_max = 0.05
     nchains_harmonic = 10
     num_epochs = 50
-    inference_method = "mike"
+    inference_method = "bayes"
     mag_selection = None
     sample_alpha = False if "IndranilVoid_" in ARGS.simname or ARGS.simname == "no_field" else True  # noqa
-    sample_beta = None
+    sample_beta = True
     no_Vext = None
     sample_Vmag_vax = False
     sample_Vmono = False
@@ -377,7 +376,6 @@ if __name__ == "__main__":
     calibration_hyperparams = {"Vext_min": -3000, "Vext_max": 3000,
                                "Vmono_min": -1000, "Vmono_max": 1000,
                                "beta_min": -10.0, "beta_max": 10.0,
-                               "sigma_v_min": 1.0, "sigma_v_max": 5000 if "IndranilVoid_" in ARGS.simname else 750.,  # noqa
                                "h_min": 0.01, "h_max": 5.0,
                                "no_Vext": False if no_Vext is None else no_Vext,        # noqa
                                "sample_Vmag_vax": sample_Vmag_vax,