How do I know when I am due for pumping?

We have a method we use for determining when you should pump your septic tank. We use a devise to measure the amount of solids and sludge at the bottom of the tank, scum that floats on the top, and the effluent waste water in-between. Depending on the measurement of each of those levels, we calculate the retention rate based on your rated daily flow. If your retention rate is less than 24 hours, you need to pump your tank immediately. What this means is IF YOU FAIL to remove the solids and scum, they will build up and start to flow into your yard. Once the solids start plugging up up your lateral lines and leach field, it will begin to back up into your house. Once you damage your treatment area field and lateral lines, major construction will have to happen for repairs which includes digging up your entire yard to replace the components of your system costing you many, many thousands. Pumping your septic tank when needed can prevent major problems.