diff --git a/client/css/pool-list-view.styl b/client/css/pool-list-view.styl
index 2daf6941..0f57649b 100644
--- a/client/css/pool-list-view.styl
+++ b/client/css/pool-list-view.styl
@@ -15,7 +15,7 @@
             background: $top-navigation-color
         .names
             width: 84%
-        .usages
+        .post-count
             text-align: center
             width: 8%
         .creation-time
diff --git a/client/html/pool.tpl b/client/html/pool.tpl
index 5af10c96..e1e5311f 100644
--- a/client/html/pool.tpl
+++ b/client/html/pool.tpl
@@ -1,5 +1,5 @@
 <div class='content-wrapper' id='pool'>
-    <h1><%- ctx.pool.first_name %></h1>
+    <h1><%- ctx.pool.names[0] %></h1>
     <nav class='buttons'><!--
         --><ul><!--
             --><li data-name='summary'><a href='<%- ctx.formatClientLink('pool', ctx.pool.id) %>'>Summary</a></li><!--
diff --git a/client/html/pools_page.tpl b/client/html/pools_page.tpl
index 6b394839..0d811808 100644
--- a/client/html/pools_page.tpl
+++ b/client/html/pools_page.tpl
@@ -11,9 +11,9 @@
                 </th>
                 <th class='post-count'>
                      <% if (ctx.parameters.query == 'sort:post-count') { %>
-                        <a href='<%- ctx.formatClientLink('pools', {query: '-sort:post-count'}) %>'>Post Count</a>
+                        <a href='<%- ctx.formatClientLink('pools', {query: '-sort:post-count'}) %>'>Post count</a>
                      <% } else { %>
-                        <a href='<%- ctx.formatClientLink('pools', {query: 'sort:post-count'}) %>'>Post Count</a>
+                        <a href='<%- ctx.formatClientLink('pools', {query: 'sort:post-count'}) %>'>Post count</a>
                      <% } %>
                      </th>
                 <th class='creation-time'>
diff --git a/client/js/controllers/pool_controller.js b/client/js/controllers/pool_controller.js
index 99e2e9bc..e243cd89 100644
--- a/client/js/controllers/pool_controller.js
+++ b/client/js/controllers/pool_controller.js
@@ -105,13 +105,13 @@ class PoolController {
         this._view.clearMessages();
         this._view.disableForm();
         e.detail.pool
-            .merge(e.detail.targetPoolName, e.detail.addAlias)
+            .merge(e.detail.targetPoolId, e.detail.addAlias)
             .then(() => {
                 this._view.showSuccess('Pool merged.');
                 this._view.enableForm();
                 router.replace(
                     uri.formatClientLink(
-                        'pool', e.detail.targetPoolName, 'merge'),
+                        'pool', e.detail.targetPoolId, 'merge'),
                     null, false);
             }, error => {
                 this._view.showError(error.message);
diff --git a/client/js/controls/pool_input_control.js b/client/js/controls/pool_input_control.js
index f53c8c96..a8272066 100644
--- a/client/js/controls/pool_input_control.js
+++ b/client/js/controls/pool_input_control.js
@@ -64,10 +64,6 @@ class PoolInputControl extends events.EventTarget {
                 verticalShift: -2
             });
 
-        // dom events
-        this._poolInputNode.addEventListener(
-            'keydown', e => this._evtInputKeyDown(e));
-
         // show
         this._hostNode.style.display = 'none';
         this._hostNode.parentNode.insertBefore(
@@ -117,23 +113,6 @@ class PoolInputControl extends events.EventTarget {
     this.dispatchEvent(new CustomEvent('change'));
   }
 
-  _evtAddPoolButtonClick(e) {
-    // TODO
-    // e.preventDefault();
-    // this.addPoolByName(this._poolInputNode.value, SOURCE_USER_INPUT);
-    // this._poolInputNode.value = '';
-  }
-
-  _evtInputKeyDown(e) {
-    // TODO
-    if (e.which == KEY_RETURN || e.which == KEY_SPACE) {
-      e.preventDefault();
-    //   this._hideAutoComplete();
-    //   this.addPoolByText(this._poolInputNode.value, SOURCE_USER_INPUT);
-    //   this._poolInputNode.value = '';
-    }
-  }
-
   _createListItemNode(pool) {
     const className = pool.category ?
                       misc.makeCssName(pool.category, 'pool') :
@@ -159,10 +138,6 @@ class PoolInputControl extends events.EventTarget {
       'href', uri.formatClientLink(
         'posts', {query: "pool:" + pool.id}));
     searchLinkNode.textContent = pool.names[0] + ' ';
-    searchLinkNode.addEventListener('click', e => {
-      // TODO?
-      // e.preventDefault();
-    });
 
     const usagesNode = document.createElement('span');
     usagesNode.classList.add('pool-usages');
diff --git a/client/js/models/post.js b/client/js/models/post.js
index e3388ece..6022ae06 100644
--- a/client/js/models/post.js
+++ b/client/js/models/post.js
@@ -8,6 +8,7 @@ const TagList = require('./tag_list.js');
 const NoteList = require('./note_list.js');
 const CommentList = require('./comment_list.js');
 const PoolList = require('./pool_list.js');
+const Pool = require('./pool.js');
 const misc = require('../util/misc.js');
 
 class Post extends events.EventTarget {
@@ -98,22 +99,36 @@ class Post extends events.EventTarget {
 
     _savePoolPosts() {
         const difference = (a, b) => a.filter(post => !b.hasPoolId(post.id));
+
+        // find the pools where the post was added or removed
         const added = difference(this.pools, this._orig._pools);
         const removed = difference(this._orig._pools, this.pools);
+
         let ops = [];
 
+        // update each pool's list of posts
         for (let pool of added) {
-            if (!pool.posts.hasPostId(this._id)) {
-                pool.posts.addById(this._id);
-                ops.push(pool.save());
-            }
+            let op = Pool.get(pool.id).then(response => {
+                if (!response.posts.hasPostId(this._id)) {
+                    response.posts.addById(this._id);
+                    return response.save();
+                } else {
+                    return Promise.resolve(response);
+                }
+            });
+            ops.push(op);
         }
 
         for (let pool of removed) {
-            if (pool.posts.hasPostId(this._id)) {
-                pool.posts.removeById(this._id);
-                ops.push(pool.save());
-            }
+            let op = Pool.get(pool.id).then(response => {
+                if (response.posts.hasPostId(this._id)) {
+                    response.posts.removeById(this._id);
+                    return response.save();
+                } else {
+                    return Promise.resolve(response);
+                }
+            });
+            ops.push(op);
         }
 
         return Promise.all(ops);
@@ -156,34 +171,34 @@ class Post extends events.EventTarget {
         }
 
         let apiPromise = this._id ?
-            api.put(uri.formatApiLink('post', this.id), detail, files) :
-            api.post(uri.formatApiLink('posts'), detail, files);
+                         api.put(uri.formatApiLink('post', this.id), detail, files) :
+                         api.post(uri.formatApiLink('posts'), detail, files);
 
         return apiPromise.then(response => {
-            if (this._pools !== this._orig._pools) {
+            if (misc.arraysDiffer(this._pools, this._orig._pools)) {
                 return this._savePoolPosts()
-                       .then(() => Promise.resolve(response));
+                           .then(() => Promise.resolve(response));
             }
             return Promise.resolve(response);
         }).then(response => {
             this._updateFromResponse(response);
             this.dispatchEvent(
-                new CustomEvent('change', {detail: {post: this}}));
+              new CustomEvent('change', {detail: {post: this}}));
             if (this._newContent) {
                 this.dispatchEvent(
-                    new CustomEvent('changeContent', {detail: {post: this}}));
+                  new CustomEvent('changeContent', {detail: {post: this}}));
             }
             if (this._newThumbnail) {
                 this.dispatchEvent(
-                    new CustomEvent('changeThumbnail', {detail: {post: this}}));
+                  new CustomEvent('changeThumbnail', {detail: {post: this}}));
             }
 
             return Promise.resolve();
         }, error => {
             if (error.response &&
-                    error.response.name === 'PostAlreadyUploadedError') {
+                error.response.name === 'PostAlreadyUploadedError') {
                 error.message =
-                    `Post already uploaded (@${error.response.otherPostId})`;
+                  `Post already uploaded (@${error.response.otherPostId})`;
             }
             return Promise.reject(error);
         });
@@ -191,118 +206,118 @@ class Post extends events.EventTarget {
 
     feature() {
         return api.post(
-                uri.formatApiLink('featured-post'),
-                {id: this._id})
-            .then(response => {
-                return Promise.resolve();
-            });
+          uri.formatApiLink('featured-post'),
+          {id: this._id})
+                  .then(response => {
+                    return Promise.resolve();
+                });
     }
 
     delete() {
         return api.delete(
-                uri.formatApiLink('post', this.id),
-                {version: this._version})
-            .then(response => {
-                this.dispatchEvent(new CustomEvent('delete', {
-                    detail: {
-                        post: this,
-                    },
-                }));
-                return Promise.resolve();
-            });
+          uri.formatApiLink('post', this.id),
+          {version: this._version})
+                  .then(response => {
+                    this.dispatchEvent(new CustomEvent('delete', {
+                        detail: {
+                            post: this,
+                        },
+                    }));
+                    return Promise.resolve();
+                });
     }
 
     merge(targetId, useOldContent) {
         return api.get(uri.formatApiLink('post', targetId))
-            .then(response => {
-                return api.post(uri.formatApiLink('post-merge'), {
-                    removeVersion: this._version,
-                    remove: this._id,
-                    mergeToVersion: response.version,
-                    mergeTo: targetId,
-                    replaceContent: useOldContent,
+                  .then(response => {
+                    return api.post(uri.formatApiLink('post-merge'), {
+                        removeVersion: this._version,
+                        remove: this._id,
+                        mergeToVersion: response.version,
+                        mergeTo: targetId,
+                        replaceContent: useOldContent,
+                    });
+                }).then(response => {
+                    this._updateFromResponse(response);
+                    this.dispatchEvent(new CustomEvent('change', {
+                        detail: {
+                            post: this,
+                        },
+                    }));
+                    return Promise.resolve();
                 });
-            }).then(response => {
-                this._updateFromResponse(response);
-                this.dispatchEvent(new CustomEvent('change', {
-                    detail: {
-                        post: this,
-                    },
-                }));
-                return Promise.resolve();
-            });
     }
 
     setScore(score) {
         return api.put(
-                uri.formatApiLink('post', this.id, 'score'),
-                {score: score})
-            .then(response => {
-                const prevFavorite = this._ownFavorite;
-                this._updateFromResponse(response);
-                if (this._ownFavorite !== prevFavorite) {
+          uri.formatApiLink('post', this.id, 'score'),
+          {score: score})
+                  .then(response => {
+                    const prevFavorite = this._ownFavorite;
+                    this._updateFromResponse(response);
+                    if (this._ownFavorite !== prevFavorite) {
+                        this.dispatchEvent(new CustomEvent('changeFavorite', {
+                            detail: {
+                                post: this,
+                            },
+                        }));
+                    }
+                    this.dispatchEvent(new CustomEvent('changeScore', {
+                        detail: {
+                            post: this,
+                        },
+                    }));
+                    return Promise.resolve();
+                });
+    }
+
+    addToFavorites() {
+        return api.post(uri.formatApiLink('post', this.id, 'favorite'))
+                  .then(response => {
+                    const prevScore = this._ownScore;
+                    this._updateFromResponse(response);
+                    if (this._ownScore !== prevScore) {
+                        this.dispatchEvent(new CustomEvent('changeScore', {
+                            detail: {
+                                post: this,
+                            },
+                        }));
+                    }
                     this.dispatchEvent(new CustomEvent('changeFavorite', {
                         detail: {
                             post: this,
                         },
                     }));
-                }
-                this.dispatchEvent(new CustomEvent('changeScore', {
-                    detail: {
-                        post: this,
-                    },
-                }));
-                return Promise.resolve();
-            });
-    }
-
-    addToFavorites() {
-        return api.post(uri.formatApiLink('post', this.id, 'favorite'))
-            .then(response => {
-                const prevScore = this._ownScore;
-                this._updateFromResponse(response);
-                if (this._ownScore !== prevScore) {
-                    this.dispatchEvent(new CustomEvent('changeScore', {
-                        detail: {
-                            post: this,
-                        },
-                    }));
-                }
-                this.dispatchEvent(new CustomEvent('changeFavorite', {
-                    detail: {
-                        post: this,
-                    },
-                }));
-                return Promise.resolve();
-            });
+                    return Promise.resolve();
+                });
     }
 
     removeFromFavorites() {
         return api.delete(uri.formatApiLink('post', this.id, 'favorite'))
-            .then(response => {
-                const prevScore = this._ownScore;
-                this._updateFromResponse(response);
-                if (this._ownScore !== prevScore) {
-                    this.dispatchEvent(new CustomEvent('changeScore', {
+                  .then(response => {
+                    const prevScore = this._ownScore;
+                    this._updateFromResponse(response);
+                    if (this._ownScore !== prevScore) {
+                        this.dispatchEvent(new CustomEvent('changeScore', {
+                            detail: {
+                                post: this,
+                            },
+                        }));
+                    }
+                    this.dispatchEvent(new CustomEvent('changeFavorite', {
                         detail: {
                             post: this,
                         },
                     }));
-                }
-                this.dispatchEvent(new CustomEvent('changeFavorite', {
-                    detail: {
-                        post: this,
-                    },
-                }));
-                return Promise.resolve();
-            });
+                    return Promise.resolve();
+                });
     }
 
     mutateContentUrl() {
         this._contentUrl =
-            this._orig._contentUrl +
-            '?bypass-cache=' +
-            Math.round(Math.random() * 1000);
+          this._orig._contentUrl +
+          '?bypass-cache=' +
+          Math.round(Math.random() * 1000);
     }
 
     _updateFromResponse(response) {
diff --git a/client/js/views/pool_merge_view.js b/client/js/views/pool_merge_view.js
index ea9fe6f2..4bbef7e6 100644
--- a/client/js/views/pool_merge_view.js
+++ b/client/js/views/pool_merge_view.js
@@ -14,6 +14,7 @@ class PoolMergeView extends events.EventTarget {
 
         this._pool = ctx.pool;
         this._hostNode = ctx.hostNode;
+        this._target_pool_id = null;
         ctx.poolNamePattern = api.getPoolNameRegex();
         views.replaceContent(this._hostNode, template(ctx));
 
@@ -22,9 +23,11 @@ class PoolMergeView extends events.EventTarget {
             this._autoCompleteControl = new PoolAutoCompleteControl(
                 this._targetPoolFieldNode,
                 {
-                    confirm: pool =>
+                    confirm: pool => {
+                        this._target_pool_id = pool.id;
                         this._autoCompleteControl.replaceSelectedText(
-                            pool.names[0], false),
+                            pool.names[0], false);
+                    }
                 });
         }
 
@@ -56,7 +59,7 @@ class PoolMergeView extends events.EventTarget {
         this.dispatchEvent(new CustomEvent('submit', {
             detail: {
                 pool: this._pool,
-                targetPoolName: this._targetPoolFieldNode.value
+                targetPoolId: this._target_pool_id
             },
         }));
     }
diff --git a/server/szurubooru/func/pools.py b/server/szurubooru/func/pools.py
index 4fc4d36d..854650a0 100644
--- a/server/szurubooru/func/pools.py
+++ b/server/szurubooru/func/pools.py
@@ -6,7 +6,6 @@ from szurubooru import config, db, model, errors, rest
 from szurubooru.func import util, pool_categories, serialization, posts
 
 
-
 class PoolNotFoundError(errors.NotFoundError):
     pass
 
@@ -35,6 +34,10 @@ class InvalidPoolDescriptionError(errors.ValidationError):
     pass
 
 
+class InvalidPoolRelationError(errors.ValidationError):
+    pass
+
+
 def _verify_name_validity(name: str) -> None:
     if util.value_exceeds_column_size(name, model.PoolName.name):
         raise InvalidPoolNameError('Name is too long.')
@@ -211,45 +214,18 @@ def merge_pools(source_pool: model.Pool, target_pool: model.Pool) -> None:
         raise InvalidPoolRelationError('Cannot merge pool with itself.')
 
     def merge_posts(source_pool_id: int, target_pool_id: int) -> None:
-        pass
-        # alias1 = model.PostPool
-        # alias2 = sa.orm.util.aliased(model.PostPool)
-        # update_stmt = (
-        #     sa.sql.expression.update(alias1)
-        #     .where(alias1.pool_id == source_pool_id))
-        # update_stmt = (
-        #     update_stmt
-        #     .where(
-        #         ~sa.exists()
-        #         .where(alias1.post_id == alias2.post_id)
-        #         .where(alias2.pool_id == target_pool_id)))
-        # update_stmt = update_stmt.values(pool_id=target_pool_id)
-        # db.session.execute(update_stmt)
-
-    def merge_relations(
-            table: model.Base, source_pool_id: int, target_pool_id: int) -> None:
-        alias1 = table
-        alias2 = sa.orm.util.aliased(table)
+        alias1 = model.PoolPost
+        alias2 = sa.orm.util.aliased(model.PoolPost)
         update_stmt = (
             sa.sql.expression.update(alias1)
-            .where(alias1.parent_id == source_pool_id)
-            .where(alias1.child_id != target_pool_id)
-            .where(
-                ~sa.exists()
-                .where(alias2.child_id == alias1.child_id)
-                .where(alias2.parent_id == target_pool_id))
-            .values(parent_id=target_pool_id))
-        db.session.execute(update_stmt)
-
+            .where(alias1.pool_id == source_pool_id))
         update_stmt = (
-            sa.sql.expression.update(alias1)
-            .where(alias1.child_id == source_pool_id)
-            .where(alias1.parent_id != target_pool_id)
+            update_stmt
             .where(
                 ~sa.exists()
-                .where(alias2.parent_id == alias1.parent_id)
-                .where(alias2.child_id == target_pool_id))
-            .values(child_id=target_pool_id))
+                .where(alias1.post_id == alias2.post_id)
+                .where(alias2.pool_id == target_pool_id)))
+        update_stmt = update_stmt.values(pool_id=target_pool_id)
         db.session.execute(update_stmt)
 
     merge_posts(source_pool.pool_id, target_pool.pool_id)
@@ -316,7 +292,6 @@ def update_pool_description(pool: model.Pool, description: str) -> None:
     pool.description = description or None
 
 
-
 def update_pool_posts(pool: model.Pool, post_ids: List[int]) -> None:
     assert pool
     if _check_post_duplication(post_ids):