diff --git a/app/src/App.tsx b/app/src/App.tsx
index ce8ed0c..4a3aba6 100644
--- a/app/src/App.tsx
+++ b/app/src/App.tsx
@@ -87,7 +87,7 @@ class App extends React.Component<Props, {}> {
               <TitleBar />
               <div style={centerContent}>
                 <div style={this.getStyles().left}>
-                  <Tree connectionId={this.props.connectionId} />
+                  <Tree />
                 </div>
                 <div style={this.getStyles().right}>
                   <Sidebar connectionId={this.props.connectionId} />
@@ -105,7 +105,7 @@ class App extends React.Component<Props, {}> {
 const mapStateToProps = (state: AppState) => {
   return {
     settingsVisible: state.tooBigReducer.settings.visible,
-    connectionId: state.tooBigReducer.connectionId,
+    connectionId: state.connection.connectionId,
   }
 }
 
diff --git a/app/src/actions/Connection.ts b/app/src/actions/Connection.ts
index 60f76c7..e1cb023 100644
--- a/app/src/actions/Connection.ts
+++ b/app/src/actions/Connection.ts
@@ -1,7 +1,9 @@
-import { ActionTypes, NodeOrder, CustomAction, AppState } from '../reducers'
+import { ActionTypes, Action, ConnectionState } from '../reducers/Connection'
 import { MqttOptions } from '../../../backend/src/DataSource'
 import { Dispatch } from 'redux'
 import { rendererEvents, addMqttConnectionEvent, makeConnectionStateEvent, removeConnection } from '../../../events'
+import { AppState } from '../reducers'
+import * as q from '../../../backend/src/Model'
 
 export const connect = (options: MqttOptions, connectionId: string) => (dispatch: Dispatch<any>, getState: () => AppState) => {
   dispatch(connecting(connectionId))
@@ -9,7 +11,9 @@ export const connect = (options: MqttOptions, connectionId: string) => (dispatch
   const event = makeConnectionStateEvent(connectionId)
   rendererEvents.subscribe(event, (dataSourceState) => {
     if (dataSourceState.connected) {
-      dispatch(connected())
+      const tree = new q.Tree()
+      tree.updateWithConnection(rendererEvents, connectionId)
+      dispatch(connected(tree))
     } else if (dataSourceState.error) {
       dispatch(showError(dataSourceState.error))
       dispatch(disconnect())
@@ -17,24 +21,27 @@ export const connect = (options: MqttOptions, connectionId: string) => (dispatch
   })
 }
 
-export const connected: () => CustomAction = ()  => ({
-  type: ActionTypes.connected,
+export const connected: (tree: q.Tree) => Action = (tree: q.Tree)  => ({
+  tree,
+  type: ActionTypes.CONNECTION_SET_CONNECTED,
 })
 
-export const connecting: (connectionId: string) => CustomAction = (connectionId: string)  => ({
+export const connecting: (connectionId: string) => Action = (connectionId: string)  => ({
   connectionId,
-  type: ActionTypes.connecting,
+  type: ActionTypes.CONNECTION_SET_CONNECTING,
 })
 
 export const showError = (error?: string) => ({
   error,
-  type: ActionTypes.showError,
+  type: ActionTypes.CONNECTION_SET_SHOW_ERROR,
 })
 
-export const disconnect = () => (dispatch: Dispatch<CustomAction>, getState: () => AppState)  => {
-  rendererEvents.emit(removeConnection, getState().tooBigReducer.connectionId)
+export const disconnect = () => (dispatch: Dispatch<Action>, getState: () => AppState)  => {
+  const { connectionId, tree } = getState().connection
+  rendererEvents.emit(removeConnection, connectionId)
+  tree && tree.stopUpdating()
 
   dispatch({
-    type: ActionTypes.disconnect,
+    type: ActionTypes.CONNECTION_SET_DISCONNECTED,
   })
 }
diff --git a/app/src/actions/Sidebar.ts b/app/src/actions/Sidebar.ts
index 25f8948..a353904 100644
--- a/app/src/actions/Sidebar.ts
+++ b/app/src/actions/Sidebar.ts
@@ -3,7 +3,9 @@ import { AppState } from '../reducers'
 import { makePublishEvent, rendererEvents } from '../../../events'
 
 export const clearRetainedTopic = () => (dispatch: Dispatch<Action>, getState: () => AppState)  => {
-  const { selectedTopic, connectionId } = getState().tooBigReducer
+  const { selectedTopic } = getState().tooBigReducer
+  const { connectionId } = getState().connection
+
   if (!selectedTopic || !connectionId) {
     return
   }
diff --git a/app/src/components/ConnectionSetup/Connection.tsx b/app/src/components/ConnectionSetup/Connection.tsx
index ba08abf..a795a8c 100644
--- a/app/src/components/ConnectionSetup/Connection.tsx
+++ b/app/src/components/ConnectionSetup/Connection.tsx
@@ -380,10 +380,10 @@ class Connection extends React.Component<Props, State> {
 
 const mapStateToProps = (state: AppState) => {
   return {
-    visible: !state.tooBigReducer.connected,
-    connected: state.tooBigReducer.connected,
-    connecting: state.tooBigReducer.connecting,
-    error: state.tooBigReducer.error,
+    visible: !state.connection.connected,
+    connected: state.connection.connected,
+    connecting: state.connection.connecting,
+    error: state.connection.error,
   }
 }
 
diff --git a/app/src/components/Sidebar/History.tsx b/app/src/components/Sidebar/History.tsx
index b6b055b..bba83e1 100644
--- a/app/src/components/Sidebar/History.tsx
+++ b/app/src/components/Sidebar/History.tsx
@@ -1,5 +1,4 @@
 import * as React from 'react'
-import * as q from '../../../../backend/src/Model'
 
 import { Badge, Typography } from '@material-ui/core'
 import { Theme, withStyles } from '@material-ui/core/styles'
diff --git a/app/src/components/Tree/Tree.tsx b/app/src/components/Tree/Tree.tsx
index 99071e2..10f2397 100644
--- a/app/src/components/Tree/Tree.tsx
+++ b/app/src/components/Tree/Tree.tsx
@@ -18,22 +18,17 @@ interface Props {
   autoExpandLimit: number
   didSelectNode?: (node: q.TreeNode) => void
   connectionId?: string
-  connected: boolean
+  tree?: q.Tree
 }
 
-interface TreeState {
-  tree: q.Tree
-  msg: any
-}
-
-class Tree extends React.Component<Props, TreeState> {
+class Tree extends React.Component<Props, {}> {
   private updateTimer?: any
   private lastUpdate: number = 0
   private perf: number = 0
 
   constructor(props: any) {
     super(props)
-    this.state = { tree: new q.Tree(), msg: {} }
+    this.state = { }
   }
 
   public time(): number {
@@ -43,11 +38,18 @@ class Tree extends React.Component<Props, TreeState> {
     return time
   }
 
-  private performanceCallback = (ms: number) => {
-    average.push(Date.now(), ms)
+  public componentWillReceiveProps(nextProps: Props) {
+    if (this.props.tree !== nextProps.tree) {
+      if (this.props.tree) {
+        this.props.tree.onMerge.unsubscribe(this.throttledTreeUpdate)
+      }
+      if (nextProps.tree) {
+        nextProps.tree.onMerge.subscribe(this.throttledTreeUpdate)
+      }
+    }
   }
 
-  public throttledTreeUpdate() {
+  public throttledTreeUpdate = () => {
     if (this.updateTimer) {
       return
     }
@@ -66,23 +68,6 @@ class Tree extends React.Component<Props, TreeState> {
     }, Math.max(0, timeUntilNextUpdate))
   }
 
-  public componentWillReceiveProps(nextProps: Props) {
-    this.registerAndUnregisterEventSubscriptionsForNewProps(nextProps)
-  }
-
-  private registerAndUnregisterEventSubscriptionsForNewProps(nextProps: Props) {
-    if (this.props.connectionId !== nextProps.connectionId) {
-      if (this.props.connectionId) {
-        this.setState({ tree: new q.Tree() })
-        rendererEvents.unsubscribeAll(makeConnectionMessageEvent(this.props.connectionId))
-        this.updateTimer && clearTimeout(this.updateTimer)
-      }
-      if (nextProps.connectionId) {
-        rendererEvents.subscribe(makeConnectionMessageEvent(nextProps.connectionId), this.handleNewData)
-      }
-    }
-  }
-
   public componentWillUnmount() {
     if (this.props.connectionId) {
       const event = makeConnectionMessageEvent(this.props.connectionId)
@@ -90,17 +75,8 @@ class Tree extends React.Component<Props, TreeState> {
     }
   }
 
-  private handleNewData = (msg: MqttMessage) => {
-    const edges = msg.topic.split('/')
-    const node = q.TreeNodeFactory.fromEdgesAndValue(edges, msg.payload)
-    node.mqttMessage = msg
-    this.state.tree.updateWithNode(node.firstNode())
-
-    this.throttledTreeUpdate()
-  }
-
   public render() {
-    if (!this.props.connected) {
+    if (!this.props.tree) {
       return null
     }
 
@@ -116,22 +92,26 @@ class Tree extends React.Component<Props, TreeState> {
           autoExpandLimit={this.props.autoExpandLimit}
           isRoot={true}
           didSelectNode={this.props.didSelectNode}
-          treeNode={this.state.tree}
+          treeNode={this.props.tree}
           name="/"
           collapsed={false}
           key="rootNode"
-          lastUpdate={this.state.tree.lastUpdate}
+          lastUpdate={this.props.tree.lastUpdate}
           performanceCallback={this.performanceCallback}
         />
       </div>
     )
   }
+
+  private performanceCallback = (ms: number) => {
+    average.push(Date.now(), ms)
+  }
 }
 
 const mapStateToProps = (state: AppState) => {
   return {
     autoExpandLimit: state.tooBigReducer.settings.autoExpandLimit,
-    connected: state.tooBigReducer.connected,
+    tree: state.connection.tree,
   }
 }
 
diff --git a/app/src/reducers/Connection.ts b/app/src/reducers/Connection.ts
new file mode 100644
index 0000000..87cfb0a
--- /dev/null
+++ b/app/src/reducers/Connection.ts
@@ -0,0 +1,88 @@
+import { Action } from 'redux'
+import { createReducer } from './lib'
+import * as q from '../../../backend/src/Model'
+import { MqttOptions } from '../../../backend/src/DataSource'
+
+export interface ConnectionState {
+  tree?: q.Tree
+  connectionOptions?: MqttOptions
+  connectionId?: string
+  error?: string
+  connected: boolean
+  connecting: boolean
+}
+
+export type Action = SetConnecting | SetConnected | SetDisconnected | ShowError
+
+export enum ActionTypes {
+  CONNECTION_SET_CONNECTING = 'CONNECTION_SET_CONNECTING',
+  CONNECTION_SET_CONNECTED = 'CONNECTION_SET_CONNECTED',
+  CONNECTION_SET_DISCONNECTED = 'CONNECTION_SET_DISCONNECTED',
+  CONNECTION_SET_SHOW_ERROR = 'CONNECTION_SET_SHOW_ERROR',
+}
+
+export interface SetConnecting {
+  type: ActionTypes.CONNECTION_SET_CONNECTING,
+  connectionId: string
+}
+
+export interface SetConnected {
+  type: ActionTypes.CONNECTION_SET_CONNECTED
+  tree: q.Tree
+}
+
+export interface SetDisconnected {
+  type: ActionTypes.CONNECTION_SET_DISCONNECTED
+}
+
+export interface ShowError {
+  type: ActionTypes.CONNECTION_SET_SHOW_ERROR
+  error?: Error
+}
+
+const initialState: ConnectionState = {
+  connected: false,
+  connecting: false,
+}
+
+export const connectionReducer = createReducer(initialState, {
+  CONNECTION_SET_CONNECTING: setConnecting,
+  CONNECTION_SET_CONNECTED: setConnected,
+  CONNECTION_SET_DISCONNECTED: setDisconnected,
+  CONNECTION_SET_SHOW_ERROR: showError,
+})
+
+function setConnecting(state: ConnectionState, action: SetConnecting) {
+  return {
+    ...state,
+    connecting: true,
+    connected: false,
+    connectionId: action.connectionId,
+  }
+}
+
+function setConnected(state: ConnectionState, action: SetConnected) {
+  return {
+    ...state,
+    connecting: false,
+    connected: true,
+    tree: action.tree,
+  }
+}
+
+function setDisconnected(state: ConnectionState, action: SetDisconnected) {
+  return {
+    ...state,
+    connecting: false,
+    connected: false,
+    connectionId: undefined,
+    tree: undefined,
+  }
+}
+
+function showError(state: ConnectionState, action: ShowError) {
+  return {
+    ...state,
+    error: action.error,
+  }
+}
diff --git a/app/src/reducers/index.ts b/app/src/reducers/index.ts
index 020530a..923d72c 100644
--- a/app/src/reducers/index.ts
+++ b/app/src/reducers/index.ts
@@ -3,20 +3,18 @@ import * as q from '../../../backend/src/Model'
 import { Action, Reducer, combineReducers } from 'redux'
 
 import { trackEvent } from '../tracking'
-import { MqttOptions } from '../../../backend/src/DataSource'
 import { PublishState, publishReducer } from './Publish'
+import { ConnectionState, connectionReducer } from './Connection'
 
 export enum ActionTypes {
-  disconnect = 'DISCONNECT',
-  showError = 'SHOW_ERROR',
+
   setAutoExpandLimit = 'SET_AUTO_EXPAND_LIMIT',
   toggleSettingsVisibility = 'TOGGLE_SETTINGS_VISIBILITY',
   setNodeOrder = 'SET_NODE_ORDER',
   selectTopic = 'SELECT_TOPIC',
   showUpdateNotification = 'SHOW_UPDATE_NOTIFICATION',
   showUpdateDetails = 'SHOW_UPDATE_DETAILS',
-  connecting = 'CONNECTING',
-  connected = 'CONNECTED',
+
 }
 
 export interface CustomAction extends Action {
@@ -26,14 +24,12 @@ export interface CustomAction extends Action {
   selectedTopic?: q.TreeNode
   showUpdateNotification?: boolean
   showUpdateDetails?: boolean
-  connectionOptions?: MqttOptions
-  connectionId?: string
-  error?: string
 }
 
 export interface AppState {
   tooBigReducer: TooBigOfState
   publish: PublishState
+  connection: ConnectionState
 }
 
 export interface TooBigOfState {
@@ -41,10 +37,6 @@ export interface TooBigOfState {
   selectedTopic?: q.TreeNode
   showUpdateNotification?: boolean
   showUpdateDetails: boolean
-  connecting: boolean
-  connected: boolean
-  error?: string
-  connectionId?: string
 }
 
 export interface SettingsState {
@@ -68,9 +60,6 @@ const initialBigState: TooBigOfState = {
   },
   selectedTopic: undefined,
   showUpdateDetails: false,
-  connected: false,
-  connecting: false,
-  error: undefined,
 }
 
 const tooBigReducer: Reducer<TooBigOfState | undefined, CustomAction> = (state = initialBigState, action) => {
@@ -134,38 +123,6 @@ const tooBigReducer: Reducer<TooBigOfState | undefined, CustomAction> = (state =
         showUpdateDetails: action.showUpdateDetails,
       }
 
-    case ActionTypes.connecting:
-      if (!action.connectionId) {
-        return state
-      }
-      return {
-        ...state,
-        connected: false,
-        connecting: true,
-        connectionId: action.connectionId,
-      }
-
-    case ActionTypes.disconnect:
-      return {
-        ...state,
-        connected: false,
-        connecting: false,
-        connectionId: undefined,
-      }
-
-    case ActionTypes.connected:
-      return {
-        ...state,
-        connected: true,
-        connecting: false,
-      }
-
-    case ActionTypes.showError:
-      return {
-        ...state,
-        error: action.error,
-      }
-
     default:
       return state
   }
@@ -174,6 +131,7 @@ const tooBigReducer: Reducer<TooBigOfState | undefined, CustomAction> = (state =
 const reducer = combineReducers({
   tooBigReducer,
   publish: publishReducer,
+  connection: connectionReducer,
 })
 
 export default reducer
diff --git a/backend/src/Model/Tree.ts b/backend/src/Model/Tree.ts
index 2f8bdf0..7fc6c4b 100644
--- a/backend/src/Model/Tree.ts
+++ b/backend/src/Model/Tree.ts
@@ -1,7 +1,29 @@
 import { Edge, TreeNode } from './'
+import { EventBusInterface, makeConnectionMessageEvent, MqttMessage } from '../../../events'
+import { TreeNodeFactory } from './TreeNodeFactory'
 
 export class Tree extends TreeNode {
+  private connectionId?: string
+  private updateSource?: EventBusInterface
   constructor() {
     super(undefined, undefined)
   }
+
+  public updateWithConnection(emitter: EventBusInterface, connectionId: string) {
+    this.updateSource = emitter
+    this.updateSource.subscribe(makeConnectionMessageEvent(connectionId), this.handleNewData)
+  }
+
+  private handleNewData = (msg: MqttMessage) => {
+    const edges = msg.topic.split('/')
+    const node = TreeNodeFactory.fromEdgesAndValue(edges, msg.payload)
+    node.mqttMessage = msg
+    this.updateWithNode(node.firstNode())
+  }
+
+  public stopUpdating() {
+    if (this.updateSource && this.connectionId) {
+      this.updateSource.unsubscribeAll(makeConnectionMessageEvent(this.connectionId))
+    }
+  }
 }
diff --git a/events/EventBus.ts b/events/EventBus.ts
index e821550..8059d56 100644
--- a/events/EventBus.ts
+++ b/events/EventBus.ts
@@ -2,7 +2,7 @@ import { IpcMain, IpcRenderer, ipcMain, ipcRenderer } from 'electron'
 
 import { Event } from './Events'
 
-interface EventBusInterface {
+export interface EventBusInterface {
   subscribe<MessageType>(event: Event<MessageType>, callback:(msg: MessageType) => void): void
   unsubscribeAll<MessageType>(event: Event<MessageType>): void
   emit<MessageType>(event: Event<MessageType>, msg: MessageType): void