diff --git a/lib/towerops/monitoring.ex b/lib/towerops/monitoring.ex
index 328bac51..32cee7b8 100644
--- a/lib/towerops/monitoring.ex
+++ b/lib/towerops/monitoring.ex
@@ -41,79 +41,82 @@ defmodule Towerops.Monitoring do
 
   @doc """
   Gets hourly statistics for equipment over a time range.
-  Uses TimescaleDB continuous aggregate for performance.
+  Calculates aggregates on-demand from monitoring_checks.
   """
   def get_hourly_stats(equipment_id, start_time, end_time) do
     query = """
     SELECT
-      bucket,
-      total_checks,
-      successful_checks,
-      failed_checks,
-      avg_response_time_ms,
-      min_response_time_ms,
-      max_response_time_ms,
-      ROUND(100.0 * successful_checks / NULLIF(total_checks, 0), 2) as uptime_percentage
-    FROM monitoring_checks_hourly
-    WHERE equipment_id = $1
-      AND bucket >= $2
-      AND bucket <= $3
+      date_trunc('hour', checked_at) as bucket,
+      COUNT(*) as total_checks,
+      COUNT(*) FILTER (WHERE status = 'success') as successful_checks,
+      COUNT(*) FILTER (WHERE status IN ('failure', 'timeout')) as failed_checks,
+      ROUND(AVG(response_time_ms)::numeric, 2) as avg_response_time_ms,
+      MIN(response_time_ms) as min_response_time_ms,
+      MAX(response_time_ms) as max_response_time_ms,
+      ROUND(100.0 * COUNT(*) FILTER (WHERE status = 'success') / NULLIF(COUNT(*), 0), 2) as uptime_percentage
+    FROM monitoring_checks
+    WHERE equipment_id = $1::uuid
+      AND checked_at >= $2
+      AND checked_at <= $3
+    GROUP BY bucket
     ORDER BY bucket ASC
     """
 
     SQL.query!(
       Repo,
       query,
-      [equipment_id, start_time, end_time]
+      [Ecto.UUID.dump!(equipment_id), start_time, end_time]
     )
   end
 
   @doc """
   Gets daily statistics for equipment over a time range.
-  Uses TimescaleDB continuous aggregate for performance.
+  Calculates aggregates on-demand from monitoring_checks.
   """
   def get_daily_stats(equipment_id, start_time, end_time) do
     query = """
     SELECT
-      bucket,
-      total_checks,
-      successful_checks,
-      failed_checks,
-      avg_response_time_ms,
-      min_response_time_ms,
-      max_response_time_ms,
-      uptime_percentage
-    FROM monitoring_checks_daily
-    WHERE equipment_id = $1
-      AND bucket >= $2
-      AND bucket <= $3
+      date_trunc('day', checked_at) as bucket,
+      COUNT(*) as total_checks,
+      COUNT(*) FILTER (WHERE status = 'success') as successful_checks,
+      COUNT(*) FILTER (WHERE status IN ('failure', 'timeout')) as failed_checks,
+      ROUND(AVG(response_time_ms)::numeric, 2) as avg_response_time_ms,
+      MIN(response_time_ms) as min_response_time_ms,
+      MAX(response_time_ms) as max_response_time_ms,
+      ROUND(100.0 * COUNT(*) FILTER (WHERE status = 'success') / NULLIF(COUNT(*), 0), 2) as uptime_percentage
+    FROM monitoring_checks
+    WHERE equipment_id = $1::uuid
+      AND checked_at >= $2
+      AND checked_at <= $3
+    GROUP BY bucket
     ORDER BY bucket ASC
     """
 
     SQL.query!(
       Repo,
       query,
-      [equipment_id, start_time, end_time]
+      [Ecto.UUID.dump!(equipment_id), start_time, end_time]
     )
   end
 
   @doc """
   Gets uptime percentage for equipment over the last N days.
+  Calculates on-demand from monitoring_checks.
   """
   def get_uptime_percentage(equipment_id, days_ago \\ 30) do
     start_time = DateTime.add(DateTime.utc_now(), -days_ago * 24 * 60 * 60, :second)
 
     query = """
     SELECT
-      AVG(uptime_percentage) as avg_uptime
-    FROM monitoring_checks_daily
-    WHERE equipment_id = $1
-      AND bucket >= $2
+      ROUND(100.0 * COUNT(*) FILTER (WHERE status = 'success') / NULLIF(COUNT(*), 0), 2) as uptime_percentage
+    FROM monitoring_checks
+    WHERE equipment_id = $1::uuid
+      AND checked_at >= $2
     """
 
-    case SQL.query!(Repo, query, [equipment_id, start_time]) do
-      %{rows: [[uptime]]} when not is_nil(uptime) ->
-        Float.round(uptime, 2)
+    case SQL.query!(Repo, query, [Ecto.UUID.dump!(equipment_id), start_time]) do
+      %{rows: [[%Decimal{} = uptime]]} ->
+        uptime |> Decimal.to_float() |> Float.round(2)
 
       _ ->
         nil
diff --git a/test/towerops/monitoring_test.exs b/test/towerops/monitoring_test.exs
index 184f71ed..f11595ab 100644
--- a/test/towerops/monitoring_test.exs
+++ b/test/towerops/monitoring_test.exs
@@ -106,40 +106,183 @@ defmodule Towerops.MonitoringTest do
       assert length(Monitoring.list_equipment_checks(equipment.id)) == 1
     end
 
-    @tag :skip
     test "get_hourly_stats/3 returns stats for equipment", %{equipment: equipment} do
-      start_time = DateTime.add(DateTime.utc_now(), -24 * 60 * 60, :second)
-      end_time = DateTime.utc_now()
+      base_time = ~U[2025-12-21 12:00:00Z]
+
+      # Create checks in two different hours
+      {:ok, _} =
+        Monitoring.create_check(%{
+          equipment_id: equipment.id,
+          status: :success,
+          response_time_ms: 50,
+          checked_at: base_time
+        })
+
+      {:ok, _} =
+        Monitoring.create_check(%{
+          equipment_id: equipment.id,
+          status: :success,
+          response_time_ms: 100,
+          checked_at: DateTime.add(base_time, 30 * 60, :second)
+        })
+
+      {:ok, _} =
+        Monitoring.create_check(%{
+          equipment_id: equipment.id,
+          status: :failure,
+          response_time_ms: nil,
+          checked_at: DateTime.add(base_time, 3600, :second)
+        })
+
+      start_time = DateTime.add(base_time, -3600, :second)
+      end_time = DateTime.add(base_time, 7200, :second)
 
-      # Skip: Requires TimescaleDB continuous aggregate which doesn't exist in test DB
       result = Monitoring.get_hourly_stats(equipment.id, start_time, end_time)
       assert %Postgrex.Result{} = result
-      assert is_list(result.rows)
+      assert length(result.rows) == 2
+
+      # First hour should have 2 successful checks
+      [first_hour | _] = result.rows
+      [_bucket, total, successful, failed, avg_response, min_response, max_response, uptime] = first_hour
+      assert total == 2
+      assert successful == 2
+      assert failed == 0
+      assert avg_response == Decimal.new("75.00")
+      assert min_response == 50
+      assert max_response == 100
+      assert uptime == Decimal.new("100.00")
     end
 
-    @tag :skip
     test "get_daily_stats/3 returns stats for equipment", %{equipment: equipment} do
-      start_time = DateTime.add(DateTime.utc_now(), -30 * 24 * 60 * 60, :second)
-      end_time = DateTime.utc_now()
+      day1 = ~U[2025-12-20 12:00:00Z]
+      day2 = ~U[2025-12-21 12:00:00Z]
+
+      # Create checks on two different days
+      {:ok, _} =
+        Monitoring.create_check(%{
+          equipment_id: equipment.id,
+          status: :success,
+          response_time_ms: 50,
+          checked_at: day1
+        })
+
+      {:ok, _} =
+        Monitoring.create_check(%{
+          equipment_id: equipment.id,
+          status: :success,
+          response_time_ms: 60,
+          checked_at: DateTime.add(day1, 3600, :second)
+        })
+
+      {:ok, _} =
+        Monitoring.create_check(%{
+          equipment_id: equipment.id,
+          status: :failure,
+          response_time_ms: nil,
+          checked_at: day2
+        })
+
+      {:ok, _} =
+        Monitoring.create_check(%{
+          equipment_id: equipment.id,
+          status: :success,
+          response_time_ms: 80,
+          checked_at: DateTime.add(day2, 3600, :second)
+        })
+
+      start_time = DateTime.add(day1, -24 * 60 * 60, :second)
+      end_time = DateTime.add(day2, 24 * 60 * 60, :second)
 
-      # Skip: Requires TimescaleDB continuous aggregate which doesn't exist in test DB
       result = Monitoring.get_daily_stats(equipment.id, start_time, end_time)
       assert %Postgrex.Result{} = result
-      assert is_list(result.rows)
+      assert length(result.rows) == 2
+
+      # First day should have 2 successful checks
+      [first_day | _] = result.rows
+      [_bucket, total, successful, failed, avg_response, _min, _max, uptime] = first_day
+      assert total == 2
+      assert successful == 2
+      assert failed == 0
+      assert avg_response == Decimal.new("55.00")
+      assert uptime == Decimal.new("100.00")
     end
 
-    @tag :skip
     test "get_uptime_percentage/1 returns uptime percentage", %{equipment: equipment} do
-      # Skip: Requires TimescaleDB continuous aggregate which doesn't exist in test DB
+      base_time = DateTime.utc_now()
+
+      # Create 3 successful and 1 failed check
+      {:ok, _} =
+        Monitoring.create_check(%{
+          equipment_id: equipment.id,
+          status: :success,
+          response_time_ms: 50,
+          checked_at: DateTime.add(base_time, -60, :second)
+        })
+
+      {:ok, _} =
+        Monitoring.create_check(%{
+          equipment_id: equipment.id,
+          status: :success,
+          response_time_ms: 60,
+          checked_at: DateTime.add(base_time, -120, :second)
+        })
+
+      {:ok, _} =
+        Monitoring.create_check(%{
+          equipment_id: equipment.id,
+          status: :failure,
+          response_time_ms: nil,
+          checked_at: DateTime.add(base_time, -180, :second)
+        })
+
+      {:ok, _} =
+        Monitoring.create_check(%{
+          equipment_id: equipment.id,
+          status: :success,
+          response_time_ms: 70,
+          checked_at: DateTime.add(base_time, -240, :second)
+        })
+
       result = Monitoring.get_uptime_percentage(equipment.id)
-      assert is_nil(result) or is_float(result)
+      assert result == 75.0
     end
 
-    @tag :skip
     test "get_uptime_percentage/2 accepts custom days parameter", %{equipment: equipment} do
-      # Skip: Requires TimescaleDB continuous aggregate which doesn't exist in test DB
+      base_time = DateTime.utc_now()
+
+      # Create checks within the last 7 days
+      {:ok, _} =
+        Monitoring.create_check(%{
+          equipment_id: equipment.id,
+          status: :success,
+          response_time_ms: 50,
+          checked_at: DateTime.add(base_time, -3 * 24 * 60 * 60, :second)
+        })
+
+      {:ok, _} =
+        Monitoring.create_check(%{
+          equipment_id: equipment.id,
+          status: :success,
+          response_time_ms: 60,
+          checked_at: DateTime.add(base_time, -5 * 24 * 60 * 60, :second)
+        })
+
+      # Create a check older than 7 days (should not be included)
+      {:ok, _} =
+        Monitoring.create_check(%{
+          equipment_id: equipment.id,
+          status: :failure,
+          response_time_ms: nil,
+          checked_at: DateTime.add(base_time, -10 * 24 * 60 * 60, :second)
+        })
+
       result = Monitoring.get_uptime_percentage(equipment.id, 7)
-      assert is_nil(result) or is_float(result)
+      assert result == 100.0
+    end
+
+    test "get_uptime_percentage/1 returns nil when no checks exist", %{equipment: equipment} do
+      result = Monitoring.get_uptime_percentage(equipment.id)
+      assert is_nil(result)
     end
   end
 
diff --git a/test/towerops/organizations/policy_test.exs b/test/towerops/organizations/policy_test.exs
index 3b97f6dc..c2fa5093 100644
--- a/test/towerops/organizations/policy_test.exs
+++ b/test/towerops/organizations/policy_test.exs
@@ -51,5 +51,64 @@ defmodule Towerops.Organizations.PolicyTest do
       assert Policy.can?(membership, :view, :site) == true
       assert Policy.can?(membership, :view, :equipment) == true
     end
+
+    test "viewer can acknowledge alerts" do
+      membership = %Membership{role: :viewer}
+
+      assert Policy.can?(membership, :acknowledge, :alert) == true
+    end
+
+    test "viewer cannot perform other actions on alerts" do
+      membership = %Membership{role: :viewer}
+
+      assert Policy.can?(membership, :create, :alert) == false
+      assert Policy.can?(membership, :edit, :alert) == false
+      assert Policy.can?(membership, :delete, :alert) == false
+    end
+
+    test "nil membership cannot do anything" do
+      assert Policy.can?(nil, :view, :organization) == false
+      assert Policy.can?(nil, :edit, :site) == false
+      assert Policy.can?(nil, :delete, :equipment) == false
+    end
+
+    test "member cannot manage memberships" do
+      membership = %Membership{role: :member}
+
+      assert Policy.can?(membership, :create, :membership) == false
+      assert Policy.can?(membership, :edit, :membership) == false
+    end
+
+    test "member cannot manage invitations" do
+      membership = %Membership{role: :member}
+
+      assert Policy.can?(membership, :create, :invitation) == false
+      assert Policy.can?(membership, :delete, :invitation) == false
+    end
+
+    test "member can list resources" do
+      membership = %Membership{role: :member}
+
+      assert Policy.can?(membership, :list, :site) == true
+      assert Policy.can?(membership, :list, :equipment) == true
+      assert Policy.can?(membership, :list, :alert) == true
+    end
+
+    test "member can create and view alerts" do
+      membership = %Membership{role: :member}
+
+      assert Policy.can?(membership, :create, :alert) == true
+      assert Policy.can?(membership, :view, :alert) == true
+      assert Policy.can?(membership, :edit, :alert) == true
+    end
+
+    test "viewer can list resources" do
+      membership = %Membership{role: :viewer}
+
+      assert Policy.can?(membership, :list, :site) == true
+      assert Policy.can?(membership, :list, :equipment) == true
+      assert Policy.can?(membership, :list, :alert) == true
+      assert Policy.can?(membership, :list, :organization) == true
+    end
   end
 end