Jack wrote:

You know it would be nice if posters here at least gave the general
area they are in as different climates affect some things in different
ways and septic use is one of them. The no 1, dont do for any area is
to not put grease on any kind in the system another is coffee
grounds.How you use and where your at determines how long your system
will operate. My wife and I lived in Duval county Florida and used a
septic tank (550 gal) for 28 years before we had problem Then it was
that the original field tiles were of cement (WWII available) and they
finely deteriorated The tank itself was only about 1/2 of solids.

"only" 1/2 ?? If a tank is half full of solids, it is on the verge of
failure.

The scum baffles go about halfway down into the tank. If it's half
full of solids, the baffles go down into the solids and the liquid
forces solids into the leach field.


Mind
you that was in Florida and the septic there have a worm in them that
eats most of the solids.

a "worm" ??? what kind of worm?


So where you live makes a difference. At
present I live in Tennessee alone and my septic of 550 gals has been
going strong now for 13 years and never ben touched. So if your tank is
constructed correctly you will know when it fills with solids before
any go into your drain field..

Exactly how will you know this, without opening the tank and inspecting
it??