You shouldn't have to do a whole lot of tank cleaning for a little while, other than your water changes. After a couple weeks or so fill a 5 gallon bucket 2/3rds full or so with tank water and squeeze out the sponge filter in that. No specific number of squeezes required, I probably do about a dozen. Then just rehook up the sponge filter to your air supply line and put it back in the tank, your good to go.