Mekanism Gas Tank Monitor - CC:Tweaked

mon = peripheral.wrap("monitor_0")
tank = peripheral.wrap("bottom")
sp = peripheral.wrap("right")
alarm = 0
message = false
ack = false
while true do
 GS = tank.getStoredGas()
 GM = tank.getMaxGas()
 GP = (GS/GM) * 100
 mon.setCursorPos(1,1)
 mon.setTextScale(5)
 message = false
 if redstone.getInput("left") == true then
   ack = true
 end
 if GP < 25 then
   if alarm == 0 then
     alarm = 1
     mon.setBackgroundColor(colors.red)
     mon.setTextColor(colors.black)
     message = false
   elseif alarm == 1 then
     alarm = 2
     out = "LOW"
     mon.setBackgroundColor(colors.black)
     mon.setTextColor(colors.red)
     message = true
   elseif alarm == 2 then
     alarm = 3
     mon.setBackgroundColor(colors.red)
     mon.setTextColor(colors.black)
     message = false
   elseif alarm == 3 then
     alarm = 0
     out = "GAS"
     mon.setBackgroundColor(colors.black)
     mon.setTextColor(colors.red)
     message = true
   end
   if ack == false then
     sp.playNote("bell",3,0)
   end
 elseif GP < 50 then
   mon.setTextColor(colors.red)
   mon.setBackgroundColor(colors.black)
   ack = false
   message = false
   os.sleep(4)
 elseif GP == 100 then
   mon.setBackgroundColor(colors.green)
   mon.setTextColor(colours.white)
   ack = false
   message = true
   out = "100%"
   os.sleep(14)
 elseif GP > 75 then
   mon.setBackgroundColor(colors.green)
   mon.setTextColor(colors.white)
   ack = false
   message = false
   os.sleep(14)
 else
   mon.setBackgroundColor(colors.yellow)
   mon.setTextColor(colors.black)
   ack = false
   message = false
   os.sleep(9)
 end

 mon.clear()
 if message == false then
   out = math.ceil(GP)
   out = (string.sub(out, -2).."%")
   if (string.len(out)) == 3 then
     out = (" "..out)
   elseif (string.len(out)) == 2 then
     out = ("  "..out)
   end
 end
 mon.write(out)
 os.sleep(1)

end