On Oct 16, 12:22 pm, "free-0-fat" wrote:
Every 3 months we add two cakes (or
packets) of yeast in one cup of sugar water, The latter keeps the "beasties"
happy. This all is per the recommendation of the installer and pumper.

Adding anything other than literal crap to the tank isn't needed,
won't help, and might hurt. From the University of Minnesota:

Septic Starters, Feeders, Cleaners and Other Additives

There is no quick fix or substitute for proper operation and regular
maintenance. Do not use starters, feeders, cleaners and other
additives. Many of these additives suggest they work via "enzyme" or
"bacterial" action.

! There's no such thing as a safe AND effective septic system
additive. !

Starters: A starter is not needed to get the bacterial action
going in the septic tank. There are naturally occurring bacteria
present in sewage.

Feeders: It is not necessary to "feed" the system additional
bacteria, yeast preparations, or other home remedies. There are
millions of bacteria and plenty of food for them entering the system
in normal sewage. If the bacterial activity level is low, figure out
what is killing them (for example, household cleaners) and correct it.
High levels of activity will return after the correction.

Cleaners: Additives effective in removing solids from the septic
tank will probably damage the soil treatment system. Some additives
may suspend the solids that would normally float to the top or settle
to the bottom of the tank in the liquid. This allows them to be
carried into the soil treatment system, where they clog pipes and soil
pores leading to partial or complete failure of the system.

Other Additives: Additives, particularly degreasers, may contain
carcinogens (cancer-causing agents) that flow directly into the
groundwater along with the treated sewage.

Many state regulations ban the use of septic system additives that
contain hazardous materials. In addition, they specify that additives
must not be used as a means of replacing or reducing the frequency of
proper maintenance and removal of scum and sludge from the septic
tank. EPA or USDA approval statements on labels only mean that the
product contains no hazardous material. It does not mean the product
is effective at what it claims to do.

! Additives and cleaners are heavily promoted to homeowners through
direct mail and telephone. Don't be misled! !