diff --git a/src/App.jsx b/src/App.jsx
index 2d667857..e0fd06b9 100644
--- a/src/App.jsx
+++ b/src/App.jsx
@@ -50,6 +50,9 @@ const nodeTypes = {
   splitter2: Splitter2Node,
   splitter3: Splitter3Node,
   bubbler: BubblerNode,
+  white_noise: SourceNode,
+  pink_noise: SourceNode,
+
 };
 
 // Defining initial nodes and edges. In the data section, we have label, but also parameters specific to the node.
@@ -608,6 +611,13 @@ export default function App() {
         break;
       case 'bubbler':
         nodeData = { ...nodeData, conversion_efficiency: '0.95', vial_efficiency: '0.9', replacement_times: '' };
+        break;
+      case 'white_noise':
+        nodeData = { ...nodeData, spectral_density: '1', sampling_rate: '' };
+        break;
+      case 'pink_noise':
+        nodeData = { ...nodeData, spectral_density: '1', num_octaves: '16', sampling_rate: '' };
+        break;
       default:
         // For any other types, just use basic data
         break;
diff --git a/src/custom_pathsim_blocks.py b/src/custom_pathsim_blocks.py
index f6031fa0..1165c40e 100644
--- a/src/custom_pathsim_blocks.py
+++ b/src/custom_pathsim_blocks.py
@@ -5,14 +5,15 @@
 
 
 class Process(ODE):
-    def __init__(self, residence_time=0, ic=0, gen=0):
+    def __init__(self, residence_time=0, initial_value=0, source_term=0):
         alpha = -1 / residence_time if residence_time != 0 else 0
         super().__init__(
-            func=lambda x, u, t: x * alpha + sum(u) + gen, initial_value=ic
+            func=lambda x, u, t: x * alpha + sum(u) + source_term,
+            initial_value=initial_value,
         )
         self.residence_time = residence_time
-        self.ic = ic
-        self.gen = gen
+        self.initial_value = initial_value
+        self.source_term = source_term
 
     def update(self, t):
         x = self.engine.get()
@@ -39,6 +40,22 @@ def update(self, t):
         self.outputs.update_from_array(self.fractions * u)
 
 
+class Splitter2(Splitter):
+    def __init__(self, f1, f2):
+        """
+        Splitter with two outputs, fractions are f1 and f2.
+        """
+        super().__init__(n=2, fractions=[f1, f2])
+
+
+class Splitter3(Splitter):
+    def __init__(self, f1, f2, f3):
+        """
+        Splitter with three outputs, fractions are f1, f2 and f3.
+        """
+        super().__init__(n=3, fractions=[f1, f2, f3])
+
+
 # BUBBLER SYSTEM
 
 
diff --git a/src/pathsim_utils.py b/src/pathsim_utils.py
index f18378c7..a7aaf476 100644
--- a/src/pathsim_utils.py
+++ b/src/pathsim_utils.py
@@ -19,8 +19,10 @@
     PID,
     Schedule,
 )
-from .custom_pathsim_blocks import Process, Splitter, Bubbler
+from pathsim.blocks.noise import WhiteNoise, PinkNoise
+from .custom_pathsim_blocks import Process, Splitter, Splitter2, Splitter3, Bubbler
 from flask import jsonify
+import inspect
 
 NAME_TO_SOLVER = {
     "SSPRK22": pathsim.solvers.SSPRK22,
@@ -34,8 +36,8 @@
     "amplifier": Amplifier,
     "amplifier_reverse": Amplifier,
     "scope": Scope,
-    "splitter2": Splitter,
-    "splitter3": Splitter,
+    "splitter2": Splitter2,
+    "splitter3": Splitter3,
     "adder": Adder,
     "adder_reverse": Adder,
     "multiplier": Multiplier,
@@ -47,6 +49,8 @@
     "function": Function,
     "delay": Delay,
     "bubbler": Bubbler,
+    "white_noise": WhiteNoise,
+    "pink_noise": PinkNoise,
 }
 
 
@@ -296,14 +300,25 @@ def auto_block_construction(node: dict, eval_namespace: dict = None) -> Block:
 
     block_class = map_str_to_object[block_type]
 
-    # skip 'self'
-    parameters_for_class = block_class.__init__.__code__.co_varnames[1:]
+    parameters_for_class = inspect.signature(block_class.__init__).parameters
+    parameters = {}
+    for k, value in parameters_for_class.items():
+        if k == "self":
+            continue
+        # Skip 'operations' for Adder, as it is handled separately
+        # https://github.com/festim-dev/fuel-cycle-sim/issues/73
+        if k in ["operations"]:
+            continue
+        user_input = node["data"][k]
+        if user_input == "":
+            if value.default is inspect._empty:
+                raise ValueError(
+                    f"expected parameter for {k} in {block_type} ({node['label']})"
+                )
+            parameters[k] = value.default
+        else:
+            parameters[k] = eval(user_input, eval_namespace)
 
-    parameters = {
-        k: eval(v, eval_namespace)
-        for k, v in node["data"].items()
-        if k in parameters_for_class
-    }
     return block_class(**parameters)
 
 
@@ -329,21 +344,15 @@ def make_blocks(
                 tau=eval(node["data"]["delay"], eval_namespace),
             )
         elif block_type == "splitter2":
-            block = Splitter(
-                n=2,
-                fractions=[
-                    eval(node["data"]["f1"], eval_namespace),
-                    eval(node["data"]["f2"], eval_namespace),
-                ],
+            block = Splitter2(
+                f1=eval(node["data"]["f1"], eval_namespace),
+                f2=eval(node["data"]["f2"], eval_namespace),
             )
         elif block_type == "splitter3":
-            block = Splitter(
-                n=3,
-                fractions=[
-                    eval(node["data"]["f1"], eval_namespace),
-                    eval(node["data"]["f2"], eval_namespace),
-                    eval(node["data"]["f3"], eval_namespace),
-                ],
+            block = Splitter3(
+                f1=eval(node["data"]["f1"], eval_namespace),
+                f2=eval(node["data"]["f2"], eval_namespace),
+                f3=eval(node["data"]["f3"], eval_namespace),
             )
         elif block_type == "bubbler":
             block, events_bubbler = create_bubbler(node)
diff --git a/src/templates/template_with_macros.py b/src/templates/template_with_macros.py
index f98480d4..9fb28e53 100644
--- a/src/templates/template_with_macros.py
+++ b/src/templates/template_with_macros.py
@@ -48,7 +48,9 @@
     iterations_max={{ solverParams["iterations_max"] }},
     log={{ solverParams["log"].capitalize() }},
     tolerance_fpi={{ solverParams["tolerance_fpi"] }},
+    {%- if solverParams["extra_params"] != '' -%}
     **{{ solverParams["extra_params"] }},
+    {%- endif -%}
 )
 
 if __name__ == "__main__":
diff --git a/test/test_backend.py b/test/test_backend.py
index ce689df7..2c46174a 100644
--- a/test/test_backend.py
+++ b/test/test_backend.py
@@ -3,7 +3,7 @@
     auto_block_construction,
     create_function,
 )
-from src.custom_pathsim_blocks import Process, Splitter
+from src.custom_pathsim_blocks import Process, Splitter2, Splitter3
 
 import pathsim.blocks
 
@@ -33,17 +33,17 @@
         "data": {"expression": "3*x**2", "label": "Function"},
     },
     "delay": {"type": "delay", "data": {"tau": "1.0", "label": "Delay"}},
-    "rng": {"type": "rng", "data": {"seed": "42", "label": "RNG"}},
+    "rng": {"type": "rng", "data": {"sampling_rate": "2", "label": "RNG"}},
     "pid": {
         "type": "pid",
-        "data": {"kp": "1.0", "ki": "0.0", "kd": "0.0", "label": "PID"},
+        "data": {"Kp": "1.0", "Ki": "0.0", "Kd": "0.0", "f_max": "100", "label": "PID"},
     },
     "process": {
         "type": "process",
         "data": {
             "residence_time": "1.0",
-            "ic": "0.0",
-            "gen": "0.0",
+            "initial_value": "0.0",
+            "source_term": "0.0",
             "label": "Process",
         },
     },
@@ -56,6 +56,23 @@
         "data": {"f1": "1/3", "f2": "1/3", "f3": "1/3", "label": "Splitter 3"},
     },
     "scope": {"type": "scope", "data": {"label": "Scope"}},
+    "white_noise": {
+        "type": "white_noise",
+        "data": {
+            "spectral_density": "1",
+            "sampling_rate": "2",
+            "label": "White Noise Source",
+        },
+    },
+    "pink_noise": {
+        "type": "pink_noise",
+        "data": {
+            "spectral_density": "1",
+            "num_octaves": "16",
+            "sampling_rate": "5",
+            "label": "Pink Noise Source",
+        },
+    },
 }
 
 
@@ -117,8 +134,10 @@ def test_create_integrator():
         ("rng", pathsim.blocks.RNG),
         ("pid", pathsim.blocks.PID),
         ("process", Process),
-        ("splitter2", Splitter),
-        ("splitter3", Splitter),
+        ("splitter2", Splitter2),
+        ("splitter3", Splitter3),
+        ("white_noise", pathsim.blocks.noise.WhiteNoise),
+        ("pink_noise", pathsim.blocks.noise.PinkNoise),
     ],
 )
 def test_auto_block_construction(node_factory, block_type, expected_class):
@@ -140,8 +159,8 @@ def test_auto_block_construction(node_factory, block_type, expected_class):
         ("rng", pathsim.blocks.RNG),
         ("pid", pathsim.blocks.PID),
         ("process", Process),
-        ("splitter2", Splitter),
-        ("splitter3", Splitter),
+        ("white_noise", pathsim.blocks.noise.WhiteNoise),
+        ("pink_noise", pathsim.blocks.noise.PinkNoise),
     ],
 )
 def test_auto_block_construction_with_var(node_factory, block_type, expected_class):