Have your tank inspected by a septic tank professional every three to five years - more frequently if your family uses a lot of water and/or a garbage disposer. You can reduce the strain on your septic system by using less water and staggering showers, clothes washing, bathing and other heavy usage.
If your smaller projects call for clear pine without any knots, you can save money by buying a lesser grade, then cutting out what you need from the clear areas between the knots. Also, when buying wood, remember that face grain is not critical for structural parts which won’t show. You can likewise save on lumber costs if you can use shorter or narrower boards, or if you only need one good side of lumber for your project.