Only simple, annual cleaning is required to maintain the Silo exterior. Use a soft bristled brush, water, or water mixed with a mild detergent to wash the plastic. When used to store non-potable water, the interior of the tank does not require any maintenance since the use of leaf guards etc. will remove vegetation before entering the tank.
It is probable that small amounts of dust or similar will enter the tanks, but the amounts will not impact on the storage or capacity of the Silo tank.