t = peripheral.wrap(tankSide)
if t==nil then
  print("No tank found!") return
end
while true do
  value = 0  max = 0
  ti = t.getTankInfo(tankSide)
  for i,j in pairs(ti) do
    for name,data in pairs(j) do
      if name=="capacity" then max = data
      elseif name=="amount" then value = data
      end
      -- print(name)  -- for debugging
    end
  end