I like using a strong bleach or PP (Potassium Permangate) solution, keeping all the regular decor, susbtrate, and also filters with media running. You can use hot water, but just as long as it's not scolding hot. Run everthing for about 30 minutes. Then rinse, and use regular water, this time adding dechlorinator (if using bleach or PP) or Hydrogen Peroxide (PP) and let it run for about 30 minutes also.