Put 2 to 3 centimetres of wood pellets in an even layer in the top sieve tray (half your index finger ) Put a couple of handfuls evenly in the base tray for maximum absorption.

Take the Poop out as normal and stir or shake the tray twice daily to make sure all the Sawdust has fallen through to the base tray.

Empty the base tray after 2 or 3 days ( or if more cats are using would have to be emptied more frequently ) Checking that the sawdust is not pushing up underneath the sieve tray.  The sawdust in the base tray can be composted either in a compost or vegetable plot or garden incinerator bin...... A worry is also a good idea

Wash out the base tray put a couple of handfuls of pellets back in evenly and pop back underneath the sieve tray and just keep the Sieve Tray topped up to 2 to 3 centimetres in depth........ Empty good Sieve pellets once every 4 to 6 weeks into a spare tray and thoroughly wash and dry before putting saved pellets back in