diff --git a/better-air-filtering/control.lua b/better-air-filtering/control.lua
index 0b6ddd1..60d35b0 100644
--- a/better-air-filtering/control.lua
+++ b/better-air-filtering/control.lua
@@ -1,12 +1,12 @@
 function onTick(event)
-    for radius = 0, 4 do
-        if event.tick % 30 == radius then
-            for _, surface in pairs(game.surfaces) do
-                local filters = surface.find_entities_filtered {
-                    name = {"air-filter-machine-1", "air-filter-machine-2", "air-filter-machine-3"}
-                }
-                updateAirFilters(surface, filters, radius)
-            end
+    local maxRadius = 4
+    local radius = event.tick % 30
+    if radius <= maxRadius then
+        for _, surface in pairs(game.surfaces) do
+            local filters = surface.find_entities_filtered {
+                name = {"air-filter-machine-1", "air-filter-machine-2", "air-filter-machine-3"}
+            }
+            updateAirFilters(surface, filters, radius)
         end
     end
 end
@@ -24,25 +24,51 @@ function updateAirFilters(surface, filters, radius)
     end
 end
 
-function iteratePerChunk(filters)
-    -- TODO implement
+function groupByChunk(entities)
+    local chunks = {}
+    for _, e in pairs(entities) do
+        local chunk = positionToChunk(e.position)
+        local chunkListX = chunks[chunk.x] or {}
+        local chunkList = chunkListX[chunk.y] or {}
+        table.insert(chunkList, e)
+        chunkListX[chunk.y] = chunkList
+        chunks[chunk.x] = chunkListX
+    end
+    local pretty_chunks = {}
+    for chunkX, t in pairs(chunks) do
+        for chunkY, l in pairs(t) do
+            print(t)
+            table.insert(pretty_chunks, {chunk={x = chunkX, y = chunkY}, entities=l})
+        end
+    end
+    return pretty_chunks
+end
+
+function positionToChunk(position)
+    return {x=math.floor(position.x / 32), y=math.floor(position.y / 32)}
+end
+
+function chunkToPosition(chunk)
+    return {x=chunk.x *32, y=chunk.y*32}
 end
 
 function movePollution(chunkFrom, chunkTo, amount)
-    -- TODO should make machine consume power to move?
+
 end
 
 function getPurificationRate(entity)
     -- TODO implement
     -- 0 if not able to run
     -- based on crafting speed and amount of power (if possible)
-    -- based on recipe? Maybe not -> machine not stronger/weaker
+end
+
+function getSucktionRate(entity)
+    return 1/4 * getPurificationRate(entity)
 end
 
 --    TODO
--- Make multiple filters in same chunk absorb balanced amount of pollution (not iterative)
 -- Make more efficient
---
+-- flow rate of machines
 
 script.on_event(defines.events.on_tick, onTick)
 
diff --git a/better-air-filtering/prototypes/entity.lua b/better-air-filtering/prototypes/entity.lua
index 93bfda9..d5ae8b2 100644
--- a/better-air-filtering/prototypes/entity.lua
+++ b/better-air-filtering/prototypes/entity.lua
@@ -73,7 +73,7 @@ data:extend({
         fixed_recipe = "filter-air",
         ingredient_count = 1,
         module_slots = 0,
-        allowed_effects=nill
+        allowed_effects=nil
     },
     {
         type = "assembling-machine",
@@ -160,12 +160,12 @@ data:extend({
         {
             type = "electric",
             usage_priority = "secondary-input",
-            drain="150kW",
+            drain="100kW",
         },
-        energy_usage = "150kW",
+        energy_usage = "50kW",
         ingredient_count = 1,
         module_slots = 0,
-        allowed_effects=nill
+        allowed_effects=nil
     },
     {
         type = "assembling-machine",
@@ -252,10 +252,10 @@ data:extend({
             usage_priority = "secondary-input",
             drain="200kW",
         },
-        energy_usage = "200kW",
+        energy_usage = "100kW",
         ingredient_count = 1,
         module_slots = 0,
-        allowed_effects=nill
+        allowed_effects=nil
     },
     {
         type = "highlight-box",
diff --git a/better-air-filtering/prototypes/item.lua b/better-air-filtering/prototypes/item.lua
index 5c36fb7..535334a 100644
--- a/better-air-filtering/prototypes/item.lua
+++ b/better-air-filtering/prototypes/item.lua
@@ -46,7 +46,7 @@ data:extend({
         order = "g[plastic-bar]-g[unused-air-filter]",
         stack_size = 10,
         fuel_category = "pollution-filter",
-        burnt_result = nill,
+        burnt_result = nil,
         fuel_value = "60MW",
     },
     {