diff --git a/src/tespy/networks/network.py b/src/tespy/networks/network.py
index 6ff268046..4cd8b40c3 100644
--- a/src/tespy/networks/network.py
+++ b/src/tespy/networks/network.py
@@ -1381,6 +1381,7 @@ def init_offdesign_params(self):
             )
             logger.debug(msg)
             df = pd.read_csv(path, sep=';', decimal='.', index_col=0)
+            df.index = df.index.astype(str)
 
             # iter through all components of this type and set data
             _individual_design_paths = {}
@@ -1400,6 +1401,9 @@ def init_offdesign_params(self):
                         _individual_design_paths[path_c] = pd.read_csv(
                             path_c, sep=';', decimal='.', index_col=0
                         )
+                        _individual_design_paths[path_c].index = (
+                            _individual_design_paths[path_c].index.astype(str)
+                        )
                     data = _individual_design_paths[path_c].loc[comp.label]
 
                 else:
@@ -1480,14 +1484,14 @@ def init_conn_design_params(self, c, df):
         """
         # match connection (source, source_id, target, target_id) on
         # connection objects of design file
+        df.index = df.index.astype(str)
         if c.label not in df.index:
             # no matches in the connections of the network and the design files
             msg = (
-                'Could not find connection %s in design case. '
-                'Please, make sure no connections have been modified or '
-                'components have been relabeled for your offdesign '
-                'calculation.'
-            ).format(c.label)
+                f"Could not find connection {c.label} in design case. Please "
+                "make sure no connections have been modified or components "
+                "havebeen relabeled for your offdesign calculation."
+            )
             logger.exception(msg)
             raise hlp.TESPyNetworkError(msg)
 
@@ -1514,9 +1518,10 @@ def init_conn_params_from_path(self, c, df):
         """
         # match connection (source, source_id, target, target_id) on
         # connection objects of design file
+        df.index = df.index.astype(str)
         if c.label not in df.index:
             # no matches in the connections of the network and the design files
-            msg = ('Could not find connection %s in init path file.').format(c.label)
+            msg = f"Could not find connection {c.label} in init path file."
             logger.debug(msg)
             return
 
diff --git a/tutorial/advanced/starting_values.py b/tutorial/advanced/starting_values.py
index da8c53de9..ad13295ec 100644
--- a/tutorial/advanced/starting_values.py
+++ b/tutorial/advanced/starting_values.py
@@ -11,10 +11,7 @@
 wf = "NH3"
 
 # network
-nw = Network(
-    fluids=["water", wf],
-    T_unit="C", p_unit="bar", h_unit="kJ / kg", m_unit="kg / s"
-    )
+nw = Network(T_unit="C", p_unit="bar", h_unit="kJ / kg", m_unit="kg / s")
 
 # components
 cycle_closer = CycleCloser("Refrigerant Cycle Closer")
@@ -50,10 +47,7 @@
 c5 = Connection(int_heatex, "out1", valve, "in1", label="5")
 c6 = Connection(valve, "out1", cycle_closer, "in1", label="6")
 
-nw.add_conns(
-    c0, c1, c2, c3, c4,
-    c5, c6
-    )
+nw.add_conns(c0, c1, c2, c3, c4, c5, c6)
 
 # heat source
 c11 = Connection(heatsource_feedflow, "out1", heatsource_pump, "in1", label="11")
@@ -78,15 +72,15 @@
 T_cons_ff = 90
 
 # consumer cycle
-c23.set_attr(T=T_cons_ff, p=10, fluid={"water": 1, wf: 0})
+c23.set_attr(T=T_cons_ff, p=10, fluid={"water": 1})
 c24.set_attr(T=T_cons_bf)
 
 # heat source cycle
-c11.set_attr(T=T_hs_ff, p=1, fluid={"water": 1, wf: 0})
+c11.set_attr(T=T_hs_ff, p=1, fluid={"water": 1})
 c13.set_attr(T=T_hs_bf, p=1)
 
 # evaporation to fully saturated gas
-c1.set_attr(x=1, fluid={"water": 0, wf: 1})
+c1.set_attr(x=1, fluid={wf: 1})
 # degree of overheating after internal heat exchanger (evaporation side)
 c2.set_attr(Td_bp=10)
 
@@ -113,6 +107,7 @@
     nw.solve("design")
 except ValueError as e:
     print(e)
+    nw._reset_topology_reduction_specifications()
 # %%[sec_4]
 import CoolProp.CoolProp as CP
 
@@ -157,7 +152,6 @@
 def generate_network_with_starting_values(wf):
     # network
     nw = Network(
-        fluids=["water", wf],
         T_unit="C", p_unit="bar", h_unit="kJ / kg", m_unit="kg / s",
         iterinfo=False
     )
@@ -196,10 +190,7 @@ def generate_network_with_starting_values(wf):
     c5 = Connection(int_heatex, "out1", valve, "in1", label="5")
     c6 = Connection(valve, "out1", cycle_closer, "in1", label="6")
 
-    nw.add_conns(
-        c0, c1, c2, c3, c4,
-        c5, c6
-        )
+    nw.add_conns(c0, c1, c2, c3, c4, c5, c6)
 
     # heat source
     c11 = Connection(heatsource_feedflow, "out1", heatsource_pump, "in1", label="11")
@@ -223,15 +214,15 @@ def generate_network_with_starting_values(wf):
     T_cons_ff = 90
 
     # consumer cycle
-    c23.set_attr(T=T_cons_ff, p=10, fluid={"water": 1, wf: 0})
+    c23.set_attr(T=T_cons_ff, p=10, fluid={"water": 1})
     c24.set_attr(T=T_cons_bf)
 
     # heat source cycle
-    c11.set_attr(T=T_hs_ff, p=1, fluid={"water": 1, wf: 0})
+    c11.set_attr(T=T_hs_ff, p=1, fluid={"water": 1})
     c13.set_attr(T=T_hs_bf, p=1)
 
     # evaporation to fully saturated gas
-    c1.set_attr(x=1, fluid={"water": 0, wf: 1})
+    c1.set_attr(x=1, fluid={wf: 1})
 
     # parametrization components
     # isentropic efficiency
diff --git a/tutorial/advanced/stepwise.py b/tutorial/advanced/stepwise.py
index ec64ea71b..d8ce42b89 100644
--- a/tutorial/advanced/stepwise.py
+++ b/tutorial/advanced/stepwise.py
@@ -42,8 +42,8 @@
 # %%[sec_5]
 from CoolProp.CoolProp import PropsSI as PSI
 p_cond = PSI("P", "Q", 1, "T", 273.15 + 95, working_fluid) / 1e5
-c0.set_attr(T=170, p=p_cond, fluid={"water": 0, working_fluid: 1})
-c20.set_attr(T=60, p=2, fluid={"water": 1, working_fluid: 0})
+c0.set_attr(T=170, p=p_cond, fluid={working_fluid: 1})
+c20.set_attr(T=60, p=2, fluid={"water": 1})
 c22.set_attr(T=90)
 
 # key design paramter
@@ -96,7 +96,7 @@
 c6.set_attr(h=h_sat)
 
 # evaporator system hot side
-c17.set_attr(T=15, fluid={"water": 1, working_fluid: 0})
+c17.set_attr(T=15, fluid={"water": 1})
 c19.set_attr(T=9, p=1.013)
 # %%[sec_11]
 nw.solve("design")
@@ -140,7 +140,7 @@
 ic.set_attr(pr1=0.99, pr2=0.98)
 hsp.set_attr(eta_s=0.75)
 # %%[sec_15]
-c0.set_attr(p=p_cond, fluid={"water": 0, working_fluid: 1})
+c0.set_attr(p=p_cond, fluid={working_fluid: 1})
 
 c6.set_attr(h=c5.h.val + 10)
 c8.set_attr(h=c5.h.val + 10)
@@ -148,7 +148,7 @@
 c7.set_attr(h=c5.h.val * 1.2)
 c9.set_attr(h=c5.h.val * 1.2)
 
-c11.set_attr(p=1.013, T=15, fluid={"water": 1, working_fluid: 0})
+c11.set_attr(p=1.013, T=15, fluid={"water": 1})
 c14.set_attr(T=30)
 # %% [sec_16]
 nw.solve("design")
diff --git a/tutorial/basics/district_heating.py b/tutorial/basics/district_heating.py
index 24d2f262e..c9c7212bb 100755
--- a/tutorial/basics/district_heating.py
+++ b/tutorial/basics/district_heating.py
@@ -6,8 +6,7 @@
 )
 from tespy.connections import Connection
 
-fluid_list = ['INCOMP::Water']
-nw = Network(fluids=fluid_list)
+nw = Network()
 nw.set_attr(T_unit='C', p_unit='bar', h_unit='kJ / kg')
 
 # central heating plant
@@ -39,7 +38,7 @@
 pipe_feed.set_attr(Q=-250, pr=0.98)
 pipe_return.set_attr(Q=-200, pr=0.98)
 
-c1.set_attr(T=90, p=10, fluid={'Water': 1})
+c1.set_attr(T=90, p=10, fluid={'INCOMP::Water': 1})
 c2.set_attr(p=13)
 c4.set_attr(T=65)
 
diff --git a/tutorial/basics/heat_pump.py b/tutorial/basics/heat_pump.py
index 771ed51d3..28951a126 100644
--- a/tutorial/basics/heat_pump.py
+++ b/tutorial/basics/heat_pump.py
@@ -2,7 +2,6 @@
 from tespy.networks import Network
 
 # create a network object with R134a as fluid
-fluid_list = ['R134a']
 my_plant = Network()
 # %%[sec_2]
 # set the unitsystem for temperatures to °C and for pressure to bar
diff --git a/tutorial/basics/rankine.py b/tutorial/basics/rankine.py
index 0e9cb137c..f7d85fa22 100755
--- a/tutorial/basics/rankine.py
+++ b/tutorial/basics/rankine.py
@@ -2,8 +2,7 @@
 from tespy.networks import Network
 
 # create a network object with R134a as fluid
-fluid_list = ['water']
-my_plant = Network(fluids=fluid_list)
+my_plant = Network()
 my_plant.set_attr(T_unit='C', p_unit='bar', h_unit='kJ / kg')
 # %%[sec_2]
 from tespy.components import (
diff --git a/tutorial/heat_pump_exergy/NH3.py b/tutorial/heat_pump_exergy/NH3.py
index 1bb8bbdc5..92a4ba8c1 100644
--- a/tutorial/heat_pump_exergy/NH3.py
+++ b/tutorial/heat_pump_exergy/NH3.py
@@ -15,15 +15,13 @@
 from tespy.tools.characteristics import load_default_char as ldc
 import numpy as np
 
-# %% network
 pamb = 1.013  # ambient pressure
 Tamb = 2.8  # ambient temperature
 
 # mean geothermal temperature (mean value of ground feed and return flow)
 Tgeo = 9.5
 
-nw = Network(fluids=['water', 'NH3'], T_unit='C', p_unit='bar',
-             h_unit='kJ / kg', m_unit='kg / s')
+nw = Network(T_unit='C', p_unit='bar', h_unit='kJ / kg', m_unit='kg / s')
 
 # %% components
 
@@ -90,15 +88,15 @@
 # %% connection parametrization
 
 # heat pump system
-cc_cd.set_attr(fluid={'water': 0, 'NH3': 1})
+cc_cd.set_attr(fluid={'NH3': 1})
 ev_cp.set_attr(Td_bp=3)
 
 # geothermal heat collector
-gh_in_ghp.set_attr(T=Tgeo + 1.5, p=1.5, fluid={'water': 1, 'NH3': 0})
+gh_in_ghp.set_attr(T=Tgeo + 1.5, p=1.5, fluid={'water': 1})
 ev_gh_out.set_attr(T=Tgeo - 1.5, p=1.5)
 
 # heating system
-cd_hs_feed.set_attr(T=40, p=2, fluid={'water': 1, 'NH3': 0})
+cd_hs_feed.set_attr(T=40, p=2, fluid={'water': 1})
 hs_ret_hsp.set_attr(T=35, p=2)
 
 # starting values
@@ -114,9 +112,11 @@
 # power bus
 char = CharLine(x=x, y=y)
 power = Bus('power input')
-power.add_comps({'comp': cp, 'char': char, 'base': 'bus'},
-                {'comp': ghp, 'char': char, 'base': 'bus'},
-                {'comp': hsp, 'char': char, 'base': 'bus'})
+power.add_comps(
+    {'comp': cp, 'char': char, 'base': 'bus'},
+    {'comp': ghp, 'char': char, 'base': 'bus'},
+    {'comp': hsp, 'char': char, 'base': 'bus'}
+)
 
 # consumer heat bus
 heat_cons = Bus('heating system')
@@ -124,8 +124,7 @@
 
 # geothermal heat bus
 heat_geo = Bus('geothermal heat')
-heat_geo.add_comps({'comp': gh_in, 'base': 'bus'},
-                   {'comp': gh_out})
+heat_geo.add_comps({'comp': gh_in, 'base': 'bus'}, {'comp': gh_out})
 
 
 nw.add_busses(power, heat_cons, heat_geo)
diff --git a/tutorial/heat_pump_exergy/NH3_calculations.py b/tutorial/heat_pump_exergy/NH3_calculations.py
index 95f452df1..a602ae0dc 100644
--- a/tutorial/heat_pump_exergy/NH3_calculations.py
+++ b/tutorial/heat_pump_exergy/NH3_calculations.py
@@ -119,9 +119,11 @@
 # power bus
 char = CharLine(x=x, y=y)
 power = Bus('power input')
-power.add_comps({'comp': cp, 'char': char, 'base': 'bus'},
-                {'comp': ghp, 'char': char, 'base': 'bus'},
-                {'comp': hsp, 'char': char, 'base': 'bus'})
+power.add_comps(
+    {'comp': cp, 'char': char, 'base': 'bus'},
+    {'comp': ghp, 'char': char, 'base': 'bus'},
+    {'comp': hsp, 'char': char, 'base': 'bus'}
+)
 
 # consumer heat bus
 heat_cons = Bus('heating system')
@@ -129,8 +131,7 @@
 
 # geothermal heat bus
 heat_geo = Bus('geothermal heat')
-heat_geo.add_comps({'comp': gh_in, 'base': 'bus'},
-                   {'comp': gh_out})
+heat_geo.add_comps({'comp': gh_in, 'base': 'bus'}, {'comp': gh_out})
 
 
 nw.add_busses(power, heat_cons, heat_geo)
@@ -178,9 +179,7 @@
 
 # %% exergy analysis
 
-ean = ExergyAnalysis(network=nw,
-                     E_F=[power, heat_geo],
-                     E_P=[heat_cons])
+ean = ExergyAnalysis(network=nw, E_F=[power, heat_geo], E_P=[heat_cons])
 ean.analyse(pamb, Tamb)
 print("\n##### EXERGY ANALYSIS #####\n")
 ean.print_results()
diff --git a/tutorial/heat_pump_exergy/R410A.py b/tutorial/heat_pump_exergy/R410A.py
index fd59e3aca..c38a7f141 100644
--- a/tutorial/heat_pump_exergy/R410A.py
+++ b/tutorial/heat_pump_exergy/R410A.py
@@ -22,8 +22,7 @@
 # mean geothermal temperature (mean value of ground feed and return flow)
 Tgeo = 9.5
 
-nw = Network(fluids=['water', 'R410A'], T_unit='C', p_unit='bar',
-             h_unit='kJ / kg', m_unit='kg / s')
+nw = Network(T_unit='C', p_unit='bar', h_unit='kJ / kg', m_unit='kg / s')
 
 # %% components
 
@@ -90,15 +89,15 @@
 # %% connection parametrization
 
 # heat pump system
-cc_cd.set_attr(fluid={'water': 0, 'R410A': 1})
+cc_cd.set_attr(fluid={'R410A': 1})
 ev_cp.set_attr(Td_bp=3)
 
 # geothermal heat collector
-gh_in_ghp.set_attr(T=Tgeo + 1.5, p=1.5, fluid={'water': 1, 'R410A': 0})
+gh_in_ghp.set_attr(T=Tgeo + 1.5, p=1.5, fluid={'water': 1})
 ev_gh_out.set_attr(T=Tgeo - 1.5, p=1.5)
 
 # heating system
-cd_hs_feed.set_attr(T=40, p=2, fluid={'water': 1, 'R410A': 0})
+cd_hs_feed.set_attr(T=40, p=2, fluid={'water': 1})
 hs_ret_hsp.set_attr(T=35, p=2)
 
 # starting values
@@ -114,9 +113,11 @@
 # power bus
 char = CharLine(x=x, y=y)
 power = Bus('power input')
-power.add_comps({'comp': cp, 'char': char, 'base': 'bus'},
-                {'comp': ghp, 'char': char, 'base': 'bus'},
-                {'comp': hsp, 'char': char, 'base': 'bus'})
+power.add_comps(
+    {'comp': cp, 'char': char, 'base': 'bus'},
+    {'comp': ghp, 'char': char, 'base': 'bus'},
+    {'comp': hsp, 'char': char, 'base': 'bus'}
+)
 
 # consumer heat bus
 heat_cons = Bus('heating system')
@@ -124,8 +125,7 @@
 
 # geothermal heat bus
 heat_geo = Bus('geothermal heat')
-heat_geo.add_comps({'comp': gh_in, 'base': 'bus'},
-                   {'comp': gh_out})
+heat_geo.add_comps({'comp': gh_in, 'base': 'bus'}, {'comp': gh_out})
 
 
 nw.add_busses(power, heat_cons, heat_geo)
diff --git a/tutorial/heat_pump_exergy/R410A_calculations.py b/tutorial/heat_pump_exergy/R410A_calculations.py
index 39575354d..457a10472 100644
--- a/tutorial/heat_pump_exergy/R410A_calculations.py
+++ b/tutorial/heat_pump_exergy/R410A_calculations.py
@@ -27,8 +27,7 @@
 # mean geothermal temperature (mean value of ground feed and return flow)
 Tgeo = 9.5
 
-nw = Network(fluids=['water', 'R410A'], T_unit='C', p_unit='bar',
-             h_unit='kJ / kg', m_unit='kg / s')
+nw = Network(T_unit='C', p_unit='bar', h_unit='kJ / kg', m_unit='kg / s')
 
 # %% components
 
@@ -95,15 +94,15 @@
 # %% connection parametrization
 
 # heat pump system
-cc_cd.set_attr(fluid={'water': 0, 'R410A': 1})
+cc_cd.set_attr(fluid={'R410A': 1})
 ev_cp.set_attr(Td_bp=3)
 
 # geothermal heat collector
-gh_in_ghp.set_attr(T=Tgeo + 1.5, p=1.5, fluid={'water': 1, 'R410A': 0})
+gh_in_ghp.set_attr(T=Tgeo + 1.5, p=1.5, fluid={'water': 1})
 ev_gh_out.set_attr(T=Tgeo - 1.5, p=1.5)
 
 # heating system
-cd_hs_feed.set_attr(T=40, p=2, fluid={'water': 1, 'R410A': 0})
+cd_hs_feed.set_attr(T=40, p=2, fluid={'water': 1})
 hs_ret_hsp.set_attr(T=35, p=2)
 
 # starting values
@@ -119,9 +118,11 @@
 # power bus
 char = CharLine(x=x, y=y)
 power = Bus('power input')
-power.add_comps({'comp': cp, 'char': char, 'base': 'bus'},
-                {'comp': ghp, 'char': char, 'base': 'bus'},
-                {'comp': hsp, 'char': char, 'base': 'bus'})
+power.add_comps(
+    {'comp': cp, 'char': char, 'base': 'bus'},
+    {'comp': ghp, 'char': char, 'base': 'bus'},
+    {'comp': hsp, 'char': char, 'base': 'bus'}
+)
 
 # consumer heat bus
 heat_cons = Bus('heating system')
@@ -129,8 +130,7 @@
 
 # geothermal heat bus
 heat_geo = Bus('geothermal heat')
-heat_geo.add_comps({'comp': gh_in, 'base': 'bus'},
-                   {'comp': gh_out})
+heat_geo.add_comps({'comp': gh_in, 'base': 'bus'}, {'comp': gh_out})
 
 
 nw.add_busses(power, heat_cons, heat_geo)
@@ -178,9 +178,7 @@
 
 # %% exergy analysis
 
-ean = ExergyAnalysis(network=nw,
-                     E_F=[power, heat_geo],
-                     E_P=[heat_cons])
+ean = ExergyAnalysis(network=nw, E_F=[power, heat_geo], E_P=[heat_cons])
 ean.analyse(pamb, Tamb)
 print("\n##### EXERGY ANALYSIS #####\n")
 ean.print_results()
diff --git a/tutorial/heat_pump_exergy/plots.py b/tutorial/heat_pump_exergy/plots.py
index b380d0287..7e4454ed5 100644
--- a/tutorial/heat_pump_exergy/plots.py
+++ b/tutorial/heat_pump_exergy/plots.py
@@ -6,8 +6,9 @@
 
 
 # color range
-colors = ['#00395b', '#74adc1', '#b54036', '#ec6707',
-          '#bfbfbf', '#999999', '#010101']
+colors = [
+    '#00395b', '#74adc1', '#b54036', '#ec6707', '#bfbfbf', '#999999', '#010101'
+]
 
 
 # %% figure 1: plot component exergy destruction