Depending on the demands you put on your septic system, it should be cleaned every 1-3 years, depending on usage. Everything you send down the drain in your sink, shower, toilet, and garbage disposal winds up in your septic tank. If you have a large family, you may need to have your tank cleaned even more frequently. Regular system care is the secret to a long-lasting septic system. The investment you make today can save you big money over time.