What size septic tank do you need?

This varies widely, but at minimum septic system installation experts recommend a 1000-gallon tank for a two-bedroom house. The typical three- or four-bedroom home generally requires a 1500-gallon tank or larger, based on use patterns and household size.

So what exactly happens inside your septic tank?

The heavier solids collect at the bottom and are contained in the tank, while the liquid sewage effluent flows out of the tank to the drainfield.