diff --git a/supervisor/facility.lua b/supervisor/facility.lua
index f418c69..65c6b09 100644
--- a/supervisor/facility.lua
+++ b/supervisor/facility.lua
@@ -45,6 +45,9 @@ function facility.new(config, cooling_conf, check_rtu_id)
         status_text = { "START UP", "initializing..." },
         all_sys_ok = false,
         allow_testing = false,
+        -- facility tanks
+        tank_defs = cooling_conf.fac_tank_defs,
+        tank_list = {},
         -- rtus
         rtu_conn_count = 0,
         rtu_list = {},
@@ -138,6 +141,97 @@ function facility.new(config, cooling_conf, check_rtu_id)
         table.insert(self.test_tone_states, false)
     end
 
+    --#region decode tank configuration
+
+    -- determine tank information
+    if cooling_conf.fac_tank_mode == 0 then
+        self.tank_defs = {}
+
+        -- on facility tank mode 0, setup tank defs to match unit tank option
+        for i = 1, config.UnitCount do
+            self.tank_defs[i] = util.trinary(cooling_conf.r_cool[i].TankConnection, 1, 0)
+        end
+
+        self.tank_list = { table.unpack(self.tank_defs) }
+    else
+        -- decode the layout of tanks from the connections definitions
+        local tank_mode = cooling_conf.fac_tank_mode
+        local tank_defs = self.tank_defs
+        local tank_list = { table.unpack(tank_defs) }
+
+        local function calc_fdef(start_idx, end_idx)
+            local first = 4
+            for i = start_idx, end_idx do
+                if self.tank_defs[i] == 2 then
+                    if i < first then first = i end
+                end
+            end
+            return first
+        end
+
+        if tank_mode == 1 then
+            -- (1) 1 total facility tank (A A A A)
+            local first_fdef = calc_fdef(1, #tank_defs)
+            for i = 1, #tank_defs do
+                if i > first_fdef and tank_defs[i] == 2 then
+                    tank_list[i] = 0
+                end
+            end
+        elseif tank_mode == 2 then
+            -- (2) 2 total facility tanks (A A A B)
+            local first_fdef = calc_fdef(1, math.min(3, #tank_defs))
+            for i = 1, #tank_defs do
+                if (i ~= 4) and (i > first_fdef) and (tank_defs[i] == 2) then
+                    tank_list[i] = 0
+                end
+            end
+        elseif tank_mode == 3 then
+            -- (3) 2 total facility tanks (A A B B)
+            for _, a in pairs({ 1, 3 }) do
+                local b = a + 1
+                if (tank_defs[a] == 2) and (tank_defs[b] == 2) then
+                    tank_list[b] = 0
+                end
+            end
+        elseif tank_mode == 4 then
+            -- (4) 2 total facility tanks (A B B B)
+            local first_fdef = calc_fdef(2, #tank_defs)
+            for i = 1, #tank_defs do
+                if (i ~= 1) and (i > first_fdef) and (tank_defs[i] == 2) then
+                    tank_list[i] = 0
+                end
+            end
+        elseif tank_mode == 5 then
+            -- (5) 3 total facility tanks (A A B C)
+            local first_fdef = calc_fdef(1, math.min(2, #tank_defs))
+            for i = 1, #tank_defs do
+                if (not (i == 3 or i == 4)) and (i > first_fdef) and (tank_defs[i] == 2) then
+                    tank_list[i] = 0
+                end
+            end
+        elseif tank_mode == 6 then
+            -- (6) 3 total facility tanks (A B B C)
+            local first_fdef = calc_fdef(2, math.min(3, #tank_defs))
+            for i = 1, #tank_defs do
+                if (not (i == 1 or i == 4)) and (i > first_fdef) and (tank_defs[i] == 2) then
+                    tank_list[i] = 0
+                end
+            end
+        elseif tank_mode == 7 then
+            -- (7) 3 total facility tanks (A B C C)
+            local first_fdef = calc_fdef(3, #tank_defs)
+            for i = 1, #tank_defs do
+                if (not (i == 1 or i == 2)) and (i > first_fdef) and (tank_defs[i] == 2) then
+                    tank_list[i] = 0
+                end
+            end
+        end
+
+        self.tank_list = tank_list
+    end
+
+    --#endregion
+
     -- PUBLIC FUNCTIONS --
 
     ---@class facility